alkalinity

Discussion in 'Reef Fishes' started by Dinky, Feb 8, 2004.

  1. Dinky

    Dinky Guest

    I'm having some difficulty wrapping my brain around alkalinity and it's
    relationship to PH. Can anyone explain it in "Aquaria for idiots" fashion,
    or point me to a place where it's explained? I'm starting to feel like I
    need to take a couple BioChem classes.

    tia

    billy

    --

    --
     
    Dinky, Feb 8, 2004
    #1
    1. Advertisements

  2. Dinky

    stoutman Guest

    pH = -log[+H]. This is a measure of the free hydrogen ion concentration in
    solution. pH > 7 is basic pH < 7 is acidic.

    Think of alkalinity as 'buffering capacity'. Or the ability of a solution
    to resist a drop in pH due to the addition of acid. The presence of Ca+
    ions and CO3-2 ions in solution add to the buffering system.

    The concentration of CaCO3 in solution accounts for 'most' of the observed
    alkalinity.

    Alkalinity is important because it prevents a sharp drop in pH due to the
    addition of acid.

    Did that help?


    "Dinky" <vincentbillNOSPAM@hotmail.NOSPAM.com> wrote in message
    news:zLfVb.15452$F23.15064@newsread2.news.pas.earthlink.net...
    > I'm having some difficulty wrapping my brain around alkalinity and it's
    > relationship to PH. Can anyone explain it in "Aquaria for idiots" fashion,
    > or point me to a place where it's explained? I'm starting to feel like I
    > need to take a couple BioChem classes.
    >
    > tia
    >
    > billy
    >
    > --
    >
    > --
    >
    >
     
    stoutman, Feb 8, 2004
    #2
    1. Advertisements

  3. Dinky

    stoutman Guest

    This may help to clear things up.

    A solution with high pH and a strong buffering capacity will drop in pH much
    slower with the addition of acid than a solution of the same pH and no
    buffering capacity.




    "stoutman" <.@.> wrote in message news:0kgVb.114897$U%5.595597@attbi_s03...
    > pH = -log[+H]. This is a measure of the free hydrogen ion concentration

    in
    > solution. pH > 7 is basic pH < 7 is acidic.
    >
    > Think of alkalinity as 'buffering capacity'. Or the ability of a solution
    > to resist a drop in pH due to the addition of acid. The presence of Ca+
    > ions and CO3-2 ions in solution add to the buffering system.
    >
    > The concentration of CaCO3 in solution accounts for 'most' of the observed
    > alkalinity.
    >
    > Alkalinity is important because it prevents a sharp drop in pH due to the
    > addition of acid.
    >
    > Did that help?
    >
    >
    > "Dinky" <vincentbillNOSPAM@hotmail.NOSPAM.com> wrote in message
    > news:zLfVb.15452$F23.15064@newsread2.news.pas.earthlink.net...
    > > I'm having some difficulty wrapping my brain around alkalinity and it's
    > > relationship to PH. Can anyone explain it in "Aquaria for idiots"

    fashion,
    > > or point me to a place where it's explained? I'm starting to feel like I
    > > need to take a couple BioChem classes.
    > >
    > > tia
    > >
    > > billy
    > >
    > > --
    > >
    > > --
    > >
    > >

    >
    >
     
    stoutman, Feb 8, 2004
    #3
  4. Dinky

    Dinky Guest

    "stoutman" <.@.> wrote in message news:0kgVb.114897$U%5.595597@attbi_s03...

    >
    > Did that help?
    >


    Yes! Very much so. I'm not sure why I didn't get it before, I've been
    running FW planted tanks, and am quite familiar with the concept of
    buffering capacity. Thank you very much.

    billy
     
    Dinky, Feb 8, 2004
    #4
  5. Dinky

    Boomer Guest

    We need to make something clear about pH drops and Alk. You can have all the alk you want
    in the world and it won't help, in regards to CO2. If CO2 increases the pH will drop, no
    mater what the Alk is. Same thing if you remove the CO2, the pH will rise an there will be
    no effect on the Alk.


    "buffering capacity "

    Bad term as Buffering Capacity isn't Alkalinity. Alk is more on the order of ANC (Acid
    Neutralizing Capacity). BC is the ability to withstand upward and downward trends in pH do
    to the addition of an acid or base.There is also a measurement called Acidity ( B_aseNC
    and test kits for it). So the combination of the two more or les is BC. But I know what
    you mean, may use the term ALK and BC interchangeably
    --
    Boomer

    Want to talk chemistry ? The Reef Chemistry Forum
    http://www.reefcentral.com/vbulletin/index.php

    Want to See More ?
    Please Join Our Growing Membership
    www.coralrealm.com

    If You See Me Running You Better Catch-Up
    "stoutman" <.@.> wrote in message news:XygVb.245342$xy6.1306359@attbi_s02...
    : This may help to clear things up.
    :
    : A solution with high pH and a strong buffering capacity will drop in pH much
    : slower with the addition of acid than a solution of the same pH and no
    : buffering capacity.
    :
    :
    :
    :
    : "stoutman" <.@.> wrote in message news:0kgVb.114897$U%5.595597@attbi_s03...
    : > pH = -log[+H]. This is a measure of the free hydrogen ion concentration
    : in
    : > solution. pH > 7 is basic pH < 7 is acidic.
    : >
    : > Think of alkalinity as 'buffering capacity'. Or the ability of a solution
    : > to resist a drop in pH due to the addition of acid. The presence of Ca+
    : > ions and CO3-2 ions in solution add to the buffering system.
    : >
    : > The concentration of CaCO3 in solution accounts for 'most' of the observed
    : > alkalinity.
    : >
    : > Alkalinity is important because it prevents a sharp drop in pH due to the
    : > addition of acid.
    : >
    : > Did that help?
    : >
    : >
    : > "Dinky" <vincentbillNOSPAM@hotmail.NOSPAM.com> wrote in message
    : > news:zLfVb.15452$F23.15064@newsread2.news.pas.earthlink.net...
    : > > I'm having some difficulty wrapping my brain around alkalinity and it's
    : > > relationship to PH. Can anyone explain it in "Aquaria for idiots"
    : fashion,
    : > > or point me to a place where it's explained? I'm starting to feel like I
    : > > need to take a couple BioChem classes.
    : > >
    : > > tia
    : > >
    : > > billy
    : > >
    : > > --
    : > >
    : > > --
    : > >
    : > >
    : >
    : >
    :
    :
     
    Boomer, Feb 8, 2004
    #5
  6. Dinky

    stoutman Guest

    >If CO2 increases the pH will drop, no mater what the Alk is. Same thing if
    you remove the CO2, the pH will rise an there will be no effect on the Alk.

    Yes, the pH will drop with the addition of CO2. Remove CO2 will cause the
    pH to rise? How do you remove CO2? Once it is in solution it forms
    carbonic acid and neutralizes some of your 'buffer'.

    >You can have all the alk you want in the world and it won't help, in

    regards to CO2.

    Wrong. Alkalinity increases your tank's ability to RESIST sharp changes in
    pH. This is what is meant by 'buffering capacity'.

    Alkalinity is the direct measurement of 'buffering capacity'.

    ..




    "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    news:102chdu2sppred8@corp.supernews.com...
    > We need to make something clear about pH drops and Alk. You can have all

    the alk you want
    > in the world and it won't help, in regards to CO2. If CO2 increases the pH

    will drop, no
    > mater what the Alk is. Same thing if you remove the CO2, the pH will rise

    an there will be
    > no effect on the Alk.
    >
    >
    > "buffering capacity "
    >
    > Bad term as Buffering Capacity isn't Alkalinity. Alk is more on the order

    of ANC (Acid
    > Neutralizing Capacity). BC is the ability to withstand upward and downward

    trends in pH do
    > to the addition of an acid or base.There is also a measurement called

    Acidity ( B_aseNC
    > and test kits for it). So the combination of the two more or les is BC.

    But I know what
    > you mean, may use the term ALK and BC interchangeably
    > --
    > Boomer
    >
    > Want to talk chemistry ? The Reef Chemistry Forum
    > http://www.reefcentral.com/vbulletin/index.php
    >
    > Want to See More ?
    > Please Join Our Growing Membership
    > www.coralrealm.com
    >
    > If You See Me Running You Better Catch-Up
    > "stoutman" <.@.> wrote in message

    news:XygVb.245342$xy6.1306359@attbi_s02...
    > : This may help to clear things up.
    > :
    > : A solution with high pH and a strong buffering capacity will drop in pH

    much
    > : slower with the addition of acid than a solution of the same pH and no
    > : buffering capacity.
    > :
    > :
    > :
    > :
    > : "stoutman" <.@.> wrote in message

    news:0kgVb.114897$U%5.595597@attbi_s03...
    > : > pH = -log[+H]. This is a measure of the free hydrogen ion

    concentration
    > : in
    > : > solution. pH > 7 is basic pH < 7 is acidic.
    > : >
    > : > Think of alkalinity as 'buffering capacity'. Or the ability of a

    solution
    > : > to resist a drop in pH due to the addition of acid. The presence of

    Ca+
    > : > ions and CO3-2 ions in solution add to the buffering system.
    > : >
    > : > The concentration of CaCO3 in solution accounts for 'most' of the

    observed
    > : > alkalinity.
    > : >
    > : > Alkalinity is important because it prevents a sharp drop in pH due to

    the
    > : > addition of acid.
    > : >
    > : > Did that help?
    > : >
    > : >
    > : > "Dinky" <vincentbillNOSPAM@hotmail.NOSPAM.com> wrote in message
    > : > news:zLfVb.15452$F23.15064@newsread2.news.pas.earthlink.net...
    > : > > I'm having some difficulty wrapping my brain around alkalinity and

    it's
    > : > > relationship to PH. Can anyone explain it in "Aquaria for idiots"
    > : fashion,
    > : > > or point me to a place where it's explained? I'm starting to feel

    like I
    > : > > need to take a couple BioChem classes.
    > : > >
    > : > > tia
    > : > >
    > : > > billy
    > : > >
    > : > > --
    > : > >
    > : > > --
    > : > >
    > : > >
    > : >
    > : >
    > :
    > :
    >
    >
     
    stoutman, Feb 8, 2004
    #6
  7. Dinky

    stoutman Guest

    Just to clear things up a little better. I'm not sure how else to make this
    any easier to understand.

    alkalinity is a measurement of 'buffering capacity'
    pH is a measurement of 'acidity/basicity'.


    "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    news:102chdu2sppred8@corp.supernews.com...
    > We need to make something clear about pH drops and Alk. You can have all

    the alk you want
    > in the world and it won't help, in regards to CO2. If CO2 increases the pH

    will drop, no
    > mater what the Alk is. Same thing if you remove the CO2, the pH will rise

    an there will be
    > no effect on the Alk.
    >
    >
    > "buffering capacity "
    >
    > Bad term as Buffering Capacity isn't Alkalinity. Alk is more on the order

    of ANC (Acid
    > Neutralizing Capacity). BC is the ability to withstand upward and downward

    trends in pH do
    > to the addition of an acid or base.There is also a measurement called

    Acidity ( B_aseNC
    > and test kits for it). So the combination of the two more or les is BC.

    But I know what
    > you mean, may use the term ALK and BC interchangeably
    > --
    > Boomer
    >
    > Want to talk chemistry ? The Reef Chemistry Forum
    > http://www.reefcentral.com/vbulletin/index.php
    >
    > Want to See More ?
    > Please Join Our Growing Membership
    > www.coralrealm.com
    >
    > If You See Me Running You Better Catch-Up
    > "stoutman" <.@.> wrote in message

    news:XygVb.245342$xy6.1306359@attbi_s02...
    > : This may help to clear things up.
    > :
    > : A solution with high pH and a strong buffering capacity will drop in pH

    much
    > : slower with the addition of acid than a solution of the same pH and no
    > : buffering capacity.
    > :
    > :
    > :
    > :
    > : "stoutman" <.@.> wrote in message

    news:0kgVb.114897$U%5.595597@attbi_s03...
    > : > pH = -log[+H]. This is a measure of the free hydrogen ion

    concentration
    > : in
    > : > solution. pH > 7 is basic pH < 7 is acidic.
    > : >
    > : > Think of alkalinity as 'buffering capacity'. Or the ability of a

    solution
    > : > to resist a drop in pH due to the addition of acid. The presence of

    Ca+
    > : > ions and CO3-2 ions in solution add to the buffering system.
    > : >
    > : > The concentration of CaCO3 in solution accounts for 'most' of the

    observed
    > : > alkalinity.
    > : >
    > : > Alkalinity is important because it prevents a sharp drop in pH due to

    the
    > : > addition of acid.
    > : >
    > : > Did that help?
    > : >
    > : >
    > : > "Dinky" <vincentbillNOSPAM@hotmail.NOSPAM.com> wrote in message
    > : > news:zLfVb.15452$F23.15064@newsread2.news.pas.earthlink.net...
    > : > > I'm having some difficulty wrapping my brain around alkalinity and

    it's
    > : > > relationship to PH. Can anyone explain it in "Aquaria for idiots"
    > : fashion,
    > : > > or point me to a place where it's explained? I'm starting to feel

    like I
    > : > > need to take a couple BioChem classes.
    > : > >
    > : > > tia
    > : > >
    > : > > billy
    > : > >
    > : > > --
    > : > >
    > : > > --
    > : > >
    > : > >
    > : >
    > : >
    > :
    > :
    >
    >
     
    stoutman, Feb 8, 2004
    #7
  8. Dinky

    Boomer Guest

    Let me make this clear you don't know what you are taking about

    "alkalinity is a measurement of 'buffering capacity'"

    No, it is the ability to neutralize an acid. BC is the ability to withstand both upward
    and downward trends in pH.

    "pH is a measurement of 'acidity/basicity'.

    No, pH is a measurement of acidity and pOH is a measurement of Basicity, if you want to
    get picky, which seems you do.


    "How do you remove CO2? "

    It is called "blowing it off" , such as with an airstone. If you have high CO2 and add an
    airstone it will drive the CO2 off raising the pH. It can be proven with a glass of water,
    a straw, some pH color indicator and an Alk test kit and if you must a CO2 test kit

    >You can have all the alk you want in the world and it won't help, in

    regards to CO2

    "Wrong. Alkalinity increases your tank's ability to RESIST sharp changes in
    pH. This is what is meant by 'buffering capacity'"

    No you are wrong and very lost. If Alk resists changes in pH then why does CO2 lower the
    pH without affecting the Alk ? CO2 has no effect on alk and alk has no effect on CO2. When
    CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any pH no matter what
    the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3

    ..
    Go ahead and pick a seawater pH and I will tell you what that ratio is. Tell me the pH and
    Alk and I will give the CO2 concentration. Give me the Alk and CO2 and I will give you
    the pH. Don't forget the temperature and Salinity.

    Alk is defined as;

    TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] + [HPO4--] +
    2[PO4---] - [H+]


    Buffering Capacity is defined as;

    BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²

    In any aqueous solution maximum BC is reached when pH= pKa. Seawaters maximum BC is at a
    pH of 6 & 9. For all practically purposes seawater has very little Buffering Capacity, if
    any at all.


    Alkalinity and Buffer Capacity are closely tied but are NOT the same thing, it is a
    misunderstanding and use of the term. Do you think water chemistry books would have
    separate sections on Alkalinity and Buffering Capacity if they were the same thing ?

    By the way do you know who you are talking to ?

    --
    Boomer

    Want to talk chemistry ? The Reef Chemistry Forum
    http://www.reefcentral.com/vbulletin/index.php

    Want to See More ?
    Please Join Our Growing Membership
    www.coralrealm.com

    If You See Me Running You Better Catch-Up
     
    Boomer, Feb 9, 2004
    #8
  9. I am sorry ahead of time I couldnt resist

    > By the way do you know who you are talking to ?



    DUH of course he doesnt or he wouldnt have argued :D


    now ive done it the king is gona slap me around for messing with the oracle :D

    --
    Richard Reynolds
    Richard.Reynolds@usa.net
     
    Richard Reynolds, Feb 9, 2004
    #9
  10. Dinky

    Toni Guest

    "Richard Reynolds" <reynolds46@cox.net> wrote in message
    news:0lHVb.16203$gl2.2728@lakeread05...
    > I am sorry ahead of time I couldnt resist
    >
    > > By the way do you know who you are talking to ?

    >
    >
    > DUH of course he doesnt or he wouldnt have argued :D
    >
    >



    But it's fun for all the rest of us to stand back and watch....
    And maybe learn something, too!


    --
    Toni
    http://www.cearbhaill.com/reef.htm
     
    Toni, Feb 9, 2004
    #10

  11. > DUH of course he doesnt or he wouldnt have argued :D


    i'm glad he didnt, made for a nice laugh to see someone tell the Great
    Oracle "YOUR WRONG" even if they were full of it. :)
     
    Dragon Slayer, Feb 9, 2004
    #11
  12. Dinky

    stoutman Guest

    Oh brother. Where to start.

    pH is the -log of the hydronium ion concentration. When the hydronium ion
    concentration is very low, your system is basic (high pH). When the
    hydronium ion concentration is very large, your system is acidic (low pH).

    pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice versa.
    But a pH of < 7 means acidic. pH > 7 means basic.
    pH can tell you something about acidity and basicity. It is a measurement
    of both, or the entire pH scale (1-14) if you will.

    >It is called "blowing it off" , such as with an airstone. If you have high

    CO2 and add an airstone it will drive the CO2 off raising the pH.

    Ok, you are going to try and 'purge' (the correct term) your CO2 out with
    air. Yeah, I guess that would work. If you intentionally put the CO2 in
    there to begin with because you must have a higher concentration of CO2 in
    your tank than in the atmosphere. I don't intentionally put CO2 in my tank.
    But I know some of you reef people due in Kalk reactors.

    >If Alk resists changes in pH then why does CO2 lower the pH without

    affecting the Alk.

    Alkalinity is buffering capacity. Your buffers begin to get weakened with
    the addition of acid until they reach a point when they can no longer
    'buffer' and the pH crashes.

    >But I know what you mean, may use the term ALK and BC interchangeably


    Do you remember writing this in an earlier post? If you believe that
    alkalinity and buffering capacity can be used interchangeably than I must be
    getting through to you.

    >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    any pH no matter what the Alk or CO2 there will be an exact ratio of
    CO2:HCO3:CO3

    Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is your
    point here?

    > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    Tell me the pH and
    > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and I

    will give you
    > the pH. Don't forget the temperature and Salinity.


    Not interested. I can find my own software to do this too.

    > Alk is defined as;
    >
    > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    [HPO4--] +
    > 2[PO4---] - [H+]


    Ahh, now we are getting somewhere. What you are showing are components of a
    'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    going in circles here? Anyway, I think you are learning something.

    > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    maximum BC is at a
    > pH of 6 & 9. For all practically purposes seawater has very little

    Buffering Capacity, if
    > any at all.


    This is the 'primary buffer' in sea water:

    H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1

    If you REALLY believe that sea water has little buffering capacity, than you
    need to do some reading on your own. I wont be able to convince you.

    > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    maximum BC is at a
    > pH of 6 & 9. For all practically purposes seawater has very little

    Buffering Capacity, if
    > any at all.


    This would be true if a monoprotic acid where used in the 'buffer', but
    carbonic acid (the primary buffering component in seawater) is a polyprotic
    acid. It has two protons that can dissociate. Therefore, it has two pKa's
    (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35. The
    pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    right in there. Is that magic? :)

    Remember that seawater is more than a mixture of just carbonate and CO2,
    there are other buffers involved that make it even more complicated I'm
    sure.

    > By the way do you know who you are talking to ?


    No. Do you?




    "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    news:102edca3c38a643@corp.supernews.com...
    > Let me make this clear you don't know what you are taking about
    >
    > "alkalinity is a measurement of 'buffering capacity'"
    >
    > No, it is the ability to neutralize an acid. BC is the ability to

    withstand both upward
    > and downward trends in pH.
    >
    > "pH is a measurement of 'acidity/basicity'.
    >
    > No, pH is a measurement of acidity and pOH is a measurement of Basicity,

    if you want to
    > get picky, which seems you do.
    >
    >
    > "How do you remove CO2? "
    >
    > It is called "blowing it off" , such as with an airstone. If you have high

    CO2 and add an
    > airstone it will drive the CO2 off raising the pH. It can be proven with a

    glass of water,
    > a straw, some pH color indicator and an Alk test kit and if you must a CO2

    test kit
    >
    > >You can have all the alk you want in the world and it won't help, in

    > regards to CO2
    >
    > "Wrong. Alkalinity increases your tank's ability to RESIST sharp changes

    in
    > pH. This is what is meant by 'buffering capacity'"
    >
    > No you are wrong and very lost. If Alk resists changes in pH then why does

    CO2 lower the
    > pH without affecting the Alk ? CO2 has no effect on alk and alk has no

    effect on CO2. When
    > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any

    pH no matter what
    > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    >
    > .
    > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    Tell me the pH and
    > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and I

    will give you
    > the pH. Don't forget the temperature and Salinity.
    >
    > Alk is defined as;
    >
    > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    [HPO4--] +
    > 2[PO4---] - [H+]
    >
    >
    > Buffering Capacity is defined as;
    >
    > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²
    >
    > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    maximum BC is at a
    > pH of 6 & 9. For all practically purposes seawater has very little

    Buffering Capacity, if
    > any at all.
    >
    >
    > Alkalinity and Buffer Capacity are closely tied but are NOT the same

    thing, it is a
    > misunderstanding and use of the term. Do you think water chemistry books

    would have
    > separate sections on Alkalinity and Buffering Capacity if they were the

    same thing ?
    >
    > By the way do you know who you are talking to ?
    >
    > --
    > Boomer
    >
    > Want to talk chemistry ? The Reef Chemistry Forum
    > http://www.reefcentral.com/vbulletin/index.php
    >
    > Want to See More ?
    > Please Join Our Growing Membership
    > www.coralrealm.com
    >
    > If You See Me Running You Better Catch-Up
    >
    >
     
    stoutman, Feb 9, 2004
    #12
  13. Boomer when you read that, just let it go.............no need bashing heads
    here, the group knows what's going on.

    kc

    "stoutman" <.@.> wrote in message news:SFNVb.204571$Rc4.1681932@attbi_s54...
    > Oh brother. Where to start.
    >
    > pH is the -log of the hydronium ion concentration. When the hydronium ion
    > concentration is very low, your system is basic (high pH). When the
    > hydronium ion concentration is very large, your system is acidic (low pH).
    >
    > pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice versa.
    > But a pH of < 7 means acidic. pH > 7 means basic.
    > pH can tell you something about acidity and basicity. It is a measurement
    > of both, or the entire pH scale (1-14) if you will.
    >
    > >It is called "blowing it off" , such as with an airstone. If you have

    high
    > CO2 and add an airstone it will drive the CO2 off raising the pH.
    >
    > Ok, you are going to try and 'purge' (the correct term) your CO2 out with
    > air. Yeah, I guess that would work. If you intentionally put the CO2 in
    > there to begin with because you must have a higher concentration of CO2 in
    > your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank.
    > But I know some of you reef people due in Kalk reactors.
    >
    > >If Alk resists changes in pH then why does CO2 lower the pH without

    > affecting the Alk.
    >
    > Alkalinity is buffering capacity. Your buffers begin to get weakened with
    > the addition of acid until they reach a point when they can no longer
    > 'buffer' and the pH crashes.
    >
    > >But I know what you mean, may use the term ALK and BC interchangeably

    >
    > Do you remember writing this in an earlier post? If you believe that
    > alkalinity and buffering capacity can be used interchangeably than I must

    be
    > getting through to you.
    >
    > >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    > any pH no matter what the Alk or CO2 there will be an exact ratio of
    > CO2:HCO3:CO3
    >
    > Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > point here?
    >
    > > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    > Tell me the pH and
    > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and

    I
    > will give you
    > > the pH. Don't forget the temperature and Salinity.

    >
    > Not interested. I can find my own software to do this too.
    >
    > > Alk is defined as;
    > >
    > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > [HPO4--] +
    > > 2[PO4---] - [H+]

    >
    > Ahh, now we are getting somewhere. What you are showing are components of

    a
    > 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    > going in circles here? Anyway, I think you are learning something.
    >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.

    >
    > This is the 'primary buffer' in sea water:
    >
    > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    >
    > If you REALLY believe that sea water has little buffering capacity, than

    you
    > need to do some reading on your own. I wont be able to convince you.
    >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.

    >
    > This would be true if a monoprotic acid where used in the 'buffer', but
    > carbonic acid (the primary buffering component in seawater) is a

    polyprotic
    > acid. It has two protons that can dissociate. Therefore, it has two

    pKa's
    > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > right in there. Is that magic? :)
    >
    > Remember that seawater is more than a mixture of just carbonate and CO2,
    > there are other buffers involved that make it even more complicated I'm
    > sure.
    >
    > > By the way do you know who you are talking to ?

    >
    > No. Do you?
    >
    >
    >
    >
    > "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    > news:102edca3c38a643@corp.supernews.com...
    > > Let me make this clear you don't know what you are taking about
    > >
    > > "alkalinity is a measurement of 'buffering capacity'"
    > >
    > > No, it is the ability to neutralize an acid. BC is the ability to

    > withstand both upward
    > > and downward trends in pH.
    > >
    > > "pH is a measurement of 'acidity/basicity'.
    > >
    > > No, pH is a measurement of acidity and pOH is a measurement of Basicity,

    > if you want to
    > > get picky, which seems you do.
    > >
    > >
    > > "How do you remove CO2? "
    > >
    > > It is called "blowing it off" , such as with an airstone. If you have

    high
    > CO2 and add an
    > > airstone it will drive the CO2 off raising the pH. It can be proven with

    a
    > glass of water,
    > > a straw, some pH color indicator and an Alk test kit and if you must a

    CO2
    > test kit
    > >
    > > >You can have all the alk you want in the world and it won't help, in

    > > regards to CO2
    > >
    > > "Wrong. Alkalinity increases your tank's ability to RESIST sharp

    changes
    > in
    > > pH. This is what is meant by 'buffering capacity'"
    > >
    > > No you are wrong and very lost. If Alk resists changes in pH then why

    does
    > CO2 lower the
    > > pH without affecting the Alk ? CO2 has no effect on alk and alk has no

    > effect on CO2. When
    > > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any

    > pH no matter what
    > > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    > >
    > > .
    > > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    > Tell me the pH and
    > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and

    I
    > will give you
    > > the pH. Don't forget the temperature and Salinity.
    > >
    > > Alk is defined as;
    > >
    > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > [HPO4--] +
    > > 2[PO4---] - [H+]
    > >
    > >
    > > Buffering Capacity is defined as;
    > >
    > > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²
    > >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.
    > >
    > >
    > > Alkalinity and Buffer Capacity are closely tied but are NOT the same

    > thing, it is a
    > > misunderstanding and use of the term. Do you think water chemistry books

    > would have
    > > separate sections on Alkalinity and Buffering Capacity if they were the

    > same thing ?
    > >
    > > By the way do you know who you are talking to ?
    > >
    > > --
    > > Boomer
    > >
    > > Want to talk chemistry ? The Reef Chemistry Forum
    > > http://www.reefcentral.com/vbulletin/index.php
    > >
    > > Want to See More ?
    > > Please Join Our Growing Membership
    > > www.coralrealm.com
    > >
    > > If You See Me Running You Better Catch-Up
    > >
    > >

    >
    >
     
    Dragon Slayer, Feb 9, 2004
    #13
  14. Dinky

    stoutman Guest

    If you knew my credentials you would laugh at yourself.


    "Dragon Slayer" <koi_man@nospam_hotmail.com> wrote in message
    news:c08a79$86iq$1@news3.infoave.net...
    > Boomer when you read that, just let it go.............no need bashing

    heads
    > here, the group knows what's going on.
    >
    > kc
    >
    > "stoutman" <.@.> wrote in message

    news:SFNVb.204571$Rc4.1681932@attbi_s54...
    > > Oh brother. Where to start.
    > >
    > > pH is the -log of the hydronium ion concentration. When the hydronium

    ion
    > > concentration is very low, your system is basic (high pH). When the
    > > hydronium ion concentration is very large, your system is acidic (low

    pH).
    > >
    > > pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice

    versa.
    > > But a pH of < 7 means acidic. pH > 7 means basic.
    > > pH can tell you something about acidity and basicity. It is a

    measurement
    > > of both, or the entire pH scale (1-14) if you will.
    > >
    > > >It is called "blowing it off" , such as with an airstone. If you have

    > high
    > > CO2 and add an airstone it will drive the CO2 off raising the pH.
    > >
    > > Ok, you are going to try and 'purge' (the correct term) your CO2 out

    with
    > > air. Yeah, I guess that would work. If you intentionally put the CO2

    in
    > > there to begin with because you must have a higher concentration of CO2

    in
    > > your tank than in the atmosphere. I don't intentionally put CO2 in my

    > tank.
    > > But I know some of you reef people due in Kalk reactors.
    > >
    > > >If Alk resists changes in pH then why does CO2 lower the pH without

    > > affecting the Alk.
    > >
    > > Alkalinity is buffering capacity. Your buffers begin to get weakened

    with
    > > the addition of acid until they reach a point when they can no longer
    > > 'buffer' and the pH crashes.
    > >
    > > >But I know what you mean, may use the term ALK and BC interchangeably

    > >
    > > Do you remember writing this in an earlier post? If you believe that
    > > alkalinity and buffering capacity can be used interchangeably than I

    must
    > be
    > > getting through to you.
    > >
    > > >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3.

    At
    > > any pH no matter what the Alk or CO2 there will be an exact ratio of
    > > CO2:HCO3:CO3
    > >
    > > Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    > your
    > > point here?
    > >
    > > > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > > Tell me the pH and
    > > > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and
    > I
    > > will give you
    > > > the pH. Don't forget the temperature and Salinity.

    > >
    > > Not interested. I can find my own software to do this too.
    > >
    > > > Alk is defined as;
    > > >
    > > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > > [HPO4--] +
    > > > 2[PO4---] - [H+]

    > >
    > > Ahh, now we are getting somewhere. What you are showing are components

    of
    > a
    > > 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    > > going in circles here? Anyway, I think you are learning something.
    > >
    > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > > maximum BC is at a
    > > > pH of 6 & 9. For all practically purposes seawater has very little

    > > Buffering Capacity, if
    > > > any at all.

    > >
    > > This is the 'primary buffer' in sea water:
    > >
    > > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    > >
    > > If you REALLY believe that sea water has little buffering capacity, than

    > you
    > > need to do some reading on your own. I wont be able to convince you.
    > >
    > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > > maximum BC is at a
    > > > pH of 6 & 9. For all practically purposes seawater has very little

    > > Buffering Capacity, if
    > > > any at all.

    > >
    > > This would be true if a monoprotic acid where used in the 'buffer', but
    > > carbonic acid (the primary buffering component in seawater) is a

    > polyprotic
    > > acid. It has two protons that can dissociate. Therefore, it has two

    > pKa's
    > > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    > The
    > > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > > right in there. Is that magic? :)
    > >
    > > Remember that seawater is more than a mixture of just carbonate and CO2,
    > > there are other buffers involved that make it even more complicated I'm
    > > sure.
    > >
    > > > By the way do you know who you are talking to ?

    > >
    > > No. Do you?
    > >
    > >
    > >
    > >
    > > "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    > > news:102edca3c38a643@corp.supernews.com...
    > > > Let me make this clear you don't know what you are taking about
    > > >
    > > > "alkalinity is a measurement of 'buffering capacity'"
    > > >
    > > > No, it is the ability to neutralize an acid. BC is the ability to

    > > withstand both upward
    > > > and downward trends in pH.
    > > >
    > > > "pH is a measurement of 'acidity/basicity'.
    > > >
    > > > No, pH is a measurement of acidity and pOH is a measurement of

    Basicity,
    > > if you want to
    > > > get picky, which seems you do.
    > > >
    > > >
    > > > "How do you remove CO2? "
    > > >
    > > > It is called "blowing it off" , such as with an airstone. If you have

    > high
    > > CO2 and add an
    > > > airstone it will drive the CO2 off raising the pH. It can be proven

    with
    > a
    > > glass of water,
    > > > a straw, some pH color indicator and an Alk test kit and if you must a

    > CO2
    > > test kit
    > > >
    > > > >You can have all the alk you want in the world and it won't help, in
    > > > regards to CO2
    > > >
    > > > "Wrong. Alkalinity increases your tank's ability to RESIST sharp

    > changes
    > > in
    > > > pH. This is what is meant by 'buffering capacity'"
    > > >
    > > > No you are wrong and very lost. If Alk resists changes in pH then why

    > does
    > > CO2 lower the
    > > > pH without affecting the Alk ? CO2 has no effect on alk and alk has no

    > > effect on CO2. When
    > > > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    any
    > > pH no matter what
    > > > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    > > >
    > > > .
    > > > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > > Tell me the pH and
    > > > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and
    > I
    > > will give you
    > > > the pH. Don't forget the temperature and Salinity.
    > > >
    > > > Alk is defined as;
    > > >
    > > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > > [HPO4--] +
    > > > 2[PO4---] - [H+]
    > > >
    > > >
    > > > Buffering Capacity is defined as;
    > > >
    > > > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka +

    [H3O+])²
    > > >
    > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > > maximum BC is at a
    > > > pH of 6 & 9. For all practically purposes seawater has very little

    > > Buffering Capacity, if
    > > > any at all.
    > > >
    > > >
    > > > Alkalinity and Buffer Capacity are closely tied but are NOT the same

    > > thing, it is a
    > > > misunderstanding and use of the term. Do you think water chemistry

    books
    > > would have
    > > > separate sections on Alkalinity and Buffering Capacity if they were

    the
    > > same thing ?
    > > >
    > > > By the way do you know who you are talking to ?
    > > >
    > > > --
    > > > Boomer
    > > >
    > > > Want to talk chemistry ? The Reef Chemistry Forum
    > > > http://www.reefcentral.com/vbulletin/index.php
    > > >
    > > > Want to See More ?
    > > > Please Join Our Growing Membership
    > > > www.coralrealm.com
    > > >
    > > > If You See Me Running You Better Catch-Up
    > > >
    > > >

    > >
    > >

    >
    >
     
    stoutman, Feb 9, 2004
    #14
  15. Dinky

    stoutman Guest

    Let me just ad.

    At the pH of seawater, the buffering capacity of carbonate is at it's
    weakest. It's strongest buffering is at a pH of 6.4 and 10.3.

    There are still other buffers in seawater other than carbonate. It is a
    very complicated system.




    "stoutman" <.@.> wrote in message news:SFNVb.204571$Rc4.1681932@attbi_s54...
    > Oh brother. Where to start.
    >
    > pH is the -log of the hydronium ion concentration. When the hydronium ion
    > concentration is very low, your system is basic (high pH). When the
    > hydronium ion concentration is very large, your system is acidic (low pH).
    >
    > pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice versa.
    > But a pH of < 7 means acidic. pH > 7 means basic.
    > pH can tell you something about acidity and basicity. It is a measurement
    > of both, or the entire pH scale (1-14) if you will.
    >
    > >It is called "blowing it off" , such as with an airstone. If you have

    high
    > CO2 and add an airstone it will drive the CO2 off raising the pH.
    >
    > Ok, you are going to try and 'purge' (the correct term) your CO2 out with
    > air. Yeah, I guess that would work. If you intentionally put the CO2 in
    > there to begin with because you must have a higher concentration of CO2 in
    > your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank.
    > But I know some of you reef people due in Kalk reactors.
    >
    > >If Alk resists changes in pH then why does CO2 lower the pH without

    > affecting the Alk.
    >
    > Alkalinity is buffering capacity. Your buffers begin to get weakened with
    > the addition of acid until they reach a point when they can no longer
    > 'buffer' and the pH crashes.
    >
    > >But I know what you mean, may use the term ALK and BC interchangeably

    >
    > Do you remember writing this in an earlier post? If you believe that
    > alkalinity and buffering capacity can be used interchangeably than I must

    be
    > getting through to you.
    >
    > >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    > any pH no matter what the Alk or CO2 there will be an exact ratio of
    > CO2:HCO3:CO3
    >
    > Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > point here?
    >
    > > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    > Tell me the pH and
    > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and

    I
    > will give you
    > > the pH. Don't forget the temperature and Salinity.

    >
    > Not interested. I can find my own software to do this too.
    >
    > > Alk is defined as;
    > >
    > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > [HPO4--] +
    > > 2[PO4---] - [H+]

    >
    > Ahh, now we are getting somewhere. What you are showing are components of

    a
    > 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    > going in circles here? Anyway, I think you are learning something.
    >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.

    >
    > This is the 'primary buffer' in sea water:
    >
    > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    >
    > If you REALLY believe that sea water has little buffering capacity, than

    you
    > need to do some reading on your own. I wont be able to convince you.
    >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.

    >
    > This would be true if a monoprotic acid where used in the 'buffer', but
    > carbonic acid (the primary buffering component in seawater) is a

    polyprotic
    > acid. It has two protons that can dissociate. Therefore, it has two

    pKa's
    > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > right in there. Is that magic? :)
    >
    > Remember that seawater is more than a mixture of just carbonate and CO2,
    > there are other buffers involved that make it even more complicated I'm
    > sure.
    >
    > > By the way do you know who you are talking to ?

    >
    > No. Do you?
    >
    >
    >
    >
    > "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    > news:102edca3c38a643@corp.supernews.com...
    > > Let me make this clear you don't know what you are taking about
    > >
    > > "alkalinity is a measurement of 'buffering capacity'"
    > >
    > > No, it is the ability to neutralize an acid. BC is the ability to

    > withstand both upward
    > > and downward trends in pH.
    > >
    > > "pH is a measurement of 'acidity/basicity'.
    > >
    > > No, pH is a measurement of acidity and pOH is a measurement of Basicity,

    > if you want to
    > > get picky, which seems you do.
    > >
    > >
    > > "How do you remove CO2? "
    > >
    > > It is called "blowing it off" , such as with an airstone. If you have

    high
    > CO2 and add an
    > > airstone it will drive the CO2 off raising the pH. It can be proven with

    a
    > glass of water,
    > > a straw, some pH color indicator and an Alk test kit and if you must a

    CO2
    > test kit
    > >
    > > >You can have all the alk you want in the world and it won't help, in

    > > regards to CO2
    > >
    > > "Wrong. Alkalinity increases your tank's ability to RESIST sharp

    changes
    > in
    > > pH. This is what is meant by 'buffering capacity'"
    > >
    > > No you are wrong and very lost. If Alk resists changes in pH then why

    does
    > CO2 lower the
    > > pH without affecting the Alk ? CO2 has no effect on alk and alk has no

    > effect on CO2. When
    > > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any

    > pH no matter what
    > > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    > >
    > > .
    > > Go ahead and pick a seawater pH and I will tell you what that ratio is.

    > Tell me the pH and
    > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and

    I
    > will give you
    > > the pH. Don't forget the temperature and Salinity.
    > >
    > > Alk is defined as;
    > >
    > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +

    > [HPO4--] +
    > > 2[PO4---] - [H+]
    > >
    > >
    > > Buffering Capacity is defined as;
    > >
    > > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²
    > >
    > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters

    > maximum BC is at a
    > > pH of 6 & 9. For all practically purposes seawater has very little

    > Buffering Capacity, if
    > > any at all.
    > >
    > >
    > > Alkalinity and Buffer Capacity are closely tied but are NOT the same

    > thing, it is a
    > > misunderstanding and use of the term. Do you think water chemistry books

    > would have
    > > separate sections on Alkalinity and Buffering Capacity if they were the

    > same thing ?
    > >
    > > By the way do you know who you are talking to ?
    > >
    > > --
    > > Boomer
    > >
    > > Want to talk chemistry ? The Reef Chemistry Forum
    > > http://www.reefcentral.com/vbulletin/index.php
    > >
    > > Want to See More ?
    > > Please Join Our Growing Membership
    > > www.coralrealm.com
    > >
    > > If You See Me Running You Better Catch-Up
    > >
    > >

    >
    >
     
    stoutman, Feb 9, 2004
    #15
  16. Dinky

    Boomer Guest

    <Alkalinity is buffering capacity. >

    No it is not, they are not calculated the same. I already gave the equations please, you
    seem to avoiding them. Please consult an aquatic chemistry book.

    ">But I know what you mean, many use the term ALK and BC interchangeably"

    Yes, I most certainly do and stated it is incorrect but I know what you mean


    <If you believe that
    alkalinity and buffering capacity can be used interchangeably than I must be
    getting through to you.>

    Please don't make me laugh. No I'm not getting through


    <Which are used in the over all 'buffering capacity'. Are we
    going in circles here? Anyway, I think you are learning something>

    No I'm not learning anything but you need to. No I'm not talking in a circle but maybe you
    are. You must have missed it, so here it is again. Buffer capacity is the ability to with
    stand upward & downward trends in pH. Alkalinity only deals with downward trends and says
    nothing of upward trends. Ever hear of an Acidity test kit ?

    <This is the 'primary buffer' in sea water:>

    H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1"

    You are lost, the reaction that it is inherent to is;........... and you are missing some
    things

    2HCO3 <--->CO2 + H20 + ***CO3***


    As far as primary "buffers" in seawater you are lost again. The principle buffers of
    seawater are HCO3, CO3 and
    B(OH4). I might add that Ion pairs are also part of the Buffer Capacity. About 1/3 of
    seawaters Buffer Capacity is due to MgCO3. Like I said you don't understand Buffer
    Capacity and Alkalinity. Seawater manuals and text books are filled with this kind of
    data.Would you like me to give a list of some ?? :)

    "If you REALLY believe that sea water has little buffering capacity, than you
    need to do some reading on your own. I wont be able to convince you."

    It doesn't if you understand the issue and it is quite clear you don't. You are the one
    that need to do allllllllllllot of reading

    ***For terms are commonly used to describe various aspects of the seawater buffer system:

    1.pH

    2. Buffering Capacity

    3. Alkalinity or Total Alkalinity

    4. Carbonate Alkalinity***

    From;
    Spotte, Seawater Aquariums the Captive Environment ( a technical text book on seawater and
    seawater aquariums)


    ***In seawater, for example, maximum Buffering Capacity appears at pH values near 6 and 9
    and seawater is buffered very little , if at all, at its normal pH of 8.2***

    From;
    Skirrow, 1975 Chemical Oceanography Vol 2

    <but
    carbonic acid (the primary buffering component in seawater) >

    Bicarbonate is the primary buffer not carbonic acid ,where on God's earth did you get that
    from. At normal temp, salinity, pH and Alk it is;

    @ 20C and 34.3 ppt salinity

    CO2 = 0.52 %

    HCO3 = 86.4 %

    CO3 = 13.09 %

    From;
    Practical Handbook of Marine Science, M.J. Kennish

    <Therefore, it has two pKa's
    (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35. The
    pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    right in there. Is that magic? :)>

    Magic !!!! it must be by your account. That is FW there pal, not seawater, lets get the
    water straight here that we are dealing with, so you aren't so lost.

    The;
    pKa1 = 6.0

    pKa2 = 9.1

    From;
    Introduction to Marine Chemistry by Riley and Chester. Also from, An Introduction to the
    Chemistry of the Sea, by Pilson

    So your equation does not work as you gave it.

    (6.0 + 9.1) / 2 = 7.55 pH Hum, maybe you would care to explain that since you seem to
    think you have all the answers.

    <Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is your
    point here?>

    It means that if the pH is 8.3 and the Alk is 4.0 meq/ l or if the is pH 8.3 and the Alk
    1.5 Meq /l, or no mater what the Alk level is, if the pH is the same, the ratio's of CO2
    to HCO3 to CO3 will be the same. So you are not lost here :)

    pH = 8.2

    Alk = 4.0 meq /l

    or

    pH = *.2

    Alk = 1.5 meq /

    The percentage or ratio is still the same for both, both will be . 0.52% CO2, 86.4 % HCO3
    and 13.09 % @ 34.3 ppt and @ 20 C

    <Yeah, I guess that would work. If you intentionally put the CO2 in
    there to begin with because you must have a higher concentration of CO2 in
    your tank than in the atmosphere. I don't intentionally put CO2 in my tank>

    It does work it is not a maybe. Intentionally !!!!! where are you coming from or where
    have you been ??? CO2 is produced by normal biological activity and is the resaon behind
    many low pH's in tanks, as is room air CO2

    <you must have a higher concentration of CO2 in
    your tank than in the atmosphere>

    What !!! CO2 does not have to be higher than ambient air .Quite often CO2 is produced in
    the water and can't leave fast enough, has one would normally expect , by simple diffusion
    to the atmosphere. It is the reason why CO2 can get so high in almost any aquatic system
    and is the same reason CO2 can get so low. Why do you think Planted FW Aquarium guys use
    CO2 injection ? As the plants can remove the CO2 faster than it can diffuse across the
    water air interface. Same for a FOT, the CO2 can accumulate faster than it can diffuse,
    thus crashing the pH

    <Not interested. I can find my own software to do this too.>

    Well go get some, as you need it, that is for sure.
    --
    Boomer

    Want to talk chemistry ? The Reef Chemistry Forum
    http://www.reefcentral.com/vbulletin/index.php

    Want to See More ?
    Please Join Our Growing Membership
    www.coralrealm.com

    If You See Me Running You Better Catch-Up
    "stoutman" <.@.> wrote in message news:SFNVb.204571$Rc4.1681932@attbi_s54...
    : Oh brother. Where to start.
    :
    : pH is the -log of the hydronium ion concentration. When the hydronium ion
    : concentration is very low, your system is basic (high pH). When the
    : hydronium ion concentration is very large, your system is acidic (low pH).
    :
    : pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice versa.
    : But a pH of < 7 means acidic. pH > 7 means basic.
    : pH can tell you something about acidity and basicity. It is a measurement
    : of both, or the entire pH scale (1-14) if you will.
    :
    : >It is called "blowing it off" , such as with an airstone. If you have high
    : CO2 and add an airstone it will drive the CO2 off raising the pH.
    :
    : Ok, you are going to try and 'purge' (the correct term) your CO2 out with
    : air. Yeah, I guess that would work. If you intentionally put the CO2 in
    : there to begin with because you must have a higher concentration of CO2 in
    : your tank than in the atmosphere. I don't intentionally put CO2 in my tank.
    : But I know some of you reef people due in Kalk reactors.
    :
    : >If Alk resists changes in pH then why does CO2 lower the pH without
    : affecting the Alk.
    :
    : Alkalinity is buffering capacity. Your buffers begin to get weakened with
    : the addition of acid until they reach a point when they can no longer
    : 'buffer' and the pH crashes.
    :
    : >But I know what you mean, may use the term ALK and BC interchangeably
    :
    : Do you remember writing this in an earlier post? If you believe that
    : alkalinity and buffering capacity can be used interchangeably than I must be
    : getting through to you.
    :
    : >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At
    : any pH no matter what the Alk or CO2 there will be an exact ratio of
    : CO2:HCO3:CO3
    :
    : Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is your
    : point here?
    :
    : > Go ahead and pick a seawater pH and I will tell you what that ratio is.
    : Tell me the pH and
    : > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and I
    : will give you
    : > the pH. Don't forget the temperature and Salinity.
    :
    : Not interested. I can find my own software to do this too.
    :
    : > Alk is defined as;
    : >
    : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : [HPO4--] +
    : > 2[PO4---] - [H+]
    :
    : Ahh, now we are getting somewhere. What you are showing are components of a
    : 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    : going in circles here? Anyway, I think you are learning something.
    :
    : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : maximum BC is at a
    : > pH of 6 & 9. For all practically purposes seawater has very little
    : Buffering Capacity, if
    : > any at all.
    :
    : This is the 'primary buffer' in sea water:
    :
    : H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    :
    : If you REALLY believe that sea water has little buffering capacity, than you
    : need to do some reading on your own. I wont be able to convince you.
    :
    : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : maximum BC is at a
    : > pH of 6 & 9. For all practically purposes seawater has very little
    : Buffering Capacity, if
    : > any at all.
    :
    : This would be true if a monoprotic acid where used in the 'buffer', but
    : carbonic acid (the primary buffering component in seawater) is a polyprotic
    : acid. It has two protons that can dissociate. Therefore, it has two pKa's
    : (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35. The
    : pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    : right in there. Is that magic? :)
    :
    : Remember that seawater is more than a mixture of just carbonate and CO2,
    : there are other buffers involved that make it even more complicated I'm
    : sure.
    :
    : > By the way do you know who you are talking to ?
    :
    : No. Do you?
    :
    :
    :
    :
    : "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    : news:102edca3c38a643@corp.supernews.com...
    : > Let me make this clear you don't know what you are taking about
    : >
    : > "alkalinity is a measurement of 'buffering capacity'"
    : >
    : > No, it is the ability to neutralize an acid. BC is the ability to
    : withstand both upward
    : > and downward trends in pH.
    : >
    : > "pH is a measurement of 'acidity/basicity'.
    : >
    : > No, pH is a measurement of acidity and pOH is a measurement of Basicity,
    : if you want to
    : > get picky, which seems you do.
    : >
    : >
    : > "How do you remove CO2? "
    : >
    : > It is called "blowing it off" , such as with an airstone. If you have high
    : CO2 and add an
    : > airstone it will drive the CO2 off raising the pH. It can be proven with a
    : glass of water,
    : > a straw, some pH color indicator and an Alk test kit and if you must a CO2
    : test kit
    : >
    : > >You can have all the alk you want in the world and it won't help, in
    : > regards to CO2
    : >
    : > "Wrong. Alkalinity increases your tank's ability to RESIST sharp changes
    : in
    : > pH. This is what is meant by 'buffering capacity'"
    : >
    : > No you are wrong and very lost. If Alk resists changes in pH then why does
    : CO2 lower the
    : > pH without affecting the Alk ? CO2 has no effect on alk and alk has no
    : effect on CO2. When
    : > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any
    : pH no matter what
    : > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    : >
    : > .
    : > Go ahead and pick a seawater pH and I will tell you what that ratio is.
    : Tell me the pH and
    : > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and I
    : will give you
    : > the pH. Don't forget the temperature and Salinity.
    : >
    : > Alk is defined as;
    : >
    : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : [HPO4--] +
    : > 2[PO4---] - [H+]
    : >
    : >
    : > Buffering Capacity is defined as;
    : >
    : > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²
    : >
    : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : maximum BC is at a
    : > pH of 6 & 9. For all practically purposes seawater has very little
    : Buffering Capacity, if
    : > any at all.
    : >
    : >
    : > Alkalinity and Buffer Capacity are closely tied but are NOT the same
    : thing, it is a
    : > misunderstanding and use of the term. Do you think water chemistry books
    : would have
    : > separate sections on Alkalinity and Buffering Capacity if they were the
    : same thing ?
    : >
    : > By the way do you know who you are talking to ?
    : >
    : > --
    : > Boomer
    : >
    : > Want to talk chemistry ? The Reef Chemistry Forum
    : > http://www.reefcentral.com/vbulletin/index.php
    : >
    : > Want to See More ?
    : > Please Join Our Growing Membership
    : > www.coralrealm.com
    : >
    : > If You See Me Running You Better Catch-Up
    : >
    : >
    :
    :
     
    Boomer, Feb 9, 2004
    #16
  17. Dinky

    Boomer Guest

    Sorry DS to late, before I say your post so Sorry in delay

    --
    Boomer

    Want to talk chemistry ? The Reef Chemistry Forum
    http://www.reefcentral.com/vbulletin/index.php

    Want to See More ?
    Please Join Our Growing Membership
    www.coralrealm.com

    If You See Me Running You Better Catch-Up
    "Dragon Slayer" <koi_man@nospam_hotmail.com> wrote in message
    news:c08a79$86iq$1@news3.infoave.net...
    : Boomer when you read that, just let it go.............no need bashing heads
    : here, the group knows what's going on.
    :
    : kc
    :
    : "stoutman" <.@.> wrote in message news:SFNVb.204571$Rc4.1681932@attbi_s54...
    : > Oh brother. Where to start.
    : >
    : > pH is the -log of the hydronium ion concentration. When the hydronium ion
    : > concentration is very low, your system is basic (high pH). When the
    : > hydronium ion concentration is very large, your system is acidic (low pH).
    : >
    : > pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice versa.
    : > But a pH of < 7 means acidic. pH > 7 means basic.
    : > pH can tell you something about acidity and basicity. It is a measurement
    : > of both, or the entire pH scale (1-14) if you will.
    : >
    : > >It is called "blowing it off" , such as with an airstone. If you have
    : high
    : > CO2 and add an airstone it will drive the CO2 off raising the pH.
    : >
    : > Ok, you are going to try and 'purge' (the correct term) your CO2 out with
    : > air. Yeah, I guess that would work. If you intentionally put the CO2 in
    : > there to begin with because you must have a higher concentration of CO2 in
    : > your tank than in the atmosphere. I don't intentionally put CO2 in my
    : tank.
    : > But I know some of you reef people due in Kalk reactors.
    : >
    : > >If Alk resists changes in pH then why does CO2 lower the pH without
    : > affecting the Alk.
    : >
    : > Alkalinity is buffering capacity. Your buffers begin to get weakened with
    : > the addition of acid until they reach a point when they can no longer
    : > 'buffer' and the pH crashes.
    : >
    : > >But I know what you mean, may use the term ALK and BC interchangeably
    : >
    : > Do you remember writing this in an earlier post? If you believe that
    : > alkalinity and buffering capacity can be used interchangeably than I must
    : be
    : > getting through to you.
    : >
    : > >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At
    : > any pH no matter what the Alk or CO2 there will be an exact ratio of
    : > CO2:HCO3:CO3
    : >
    : > Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is
    : your
    : > point here?
    : >
    : > > Go ahead and pick a seawater pH and I will tell you what that ratio is.
    : > Tell me the pH and
    : > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and
    : I
    : > will give you
    : > > the pH. Don't forget the temperature and Salinity.
    : >
    : > Not interested. I can find my own software to do this too.
    : >
    : > > Alk is defined as;
    : > >
    : > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : > [HPO4--] +
    : > > 2[PO4---] - [H+]
    : >
    : > Ahh, now we are getting somewhere. What you are showing are components of
    : a
    : > 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    : > going in circles here? Anyway, I think you are learning something.
    : >
    : > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > maximum BC is at a
    : > > pH of 6 & 9. For all practically purposes seawater has very little
    : > Buffering Capacity, if
    : > > any at all.
    : >
    : > This is the 'primary buffer' in sea water:
    : >
    : > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    : >
    : > If you REALLY believe that sea water has little buffering capacity, than
    : you
    : > need to do some reading on your own. I wont be able to convince you.
    : >
    : > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > maximum BC is at a
    : > > pH of 6 & 9. For all practically purposes seawater has very little
    : > Buffering Capacity, if
    : > > any at all.
    : >
    : > This would be true if a monoprotic acid where used in the 'buffer', but
    : > carbonic acid (the primary buffering component in seawater) is a
    : polyprotic
    : > acid. It has two protons that can dissociate. Therefore, it has two
    : pKa's
    : > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.
    : The
    : > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    : > right in there. Is that magic? :)
    : >
    : > Remember that seawater is more than a mixture of just carbonate and CO2,
    : > there are other buffers involved that make it even more complicated I'm
    : > sure.
    : >
    : > > By the way do you know who you are talking to ?
    : >
    : > No. Do you?
    : >
    : >
    : >
    : >
    : > "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    : > news:102edca3c38a643@corp.supernews.com...
    : > > Let me make this clear you don't know what you are taking about
    : > >
    : > > "alkalinity is a measurement of 'buffering capacity'"
    : > >
    : > > No, it is the ability to neutralize an acid. BC is the ability to
    : > withstand both upward
    : > > and downward trends in pH.
    : > >
    : > > "pH is a measurement of 'acidity/basicity'.
    : > >
    : > > No, pH is a measurement of acidity and pOH is a measurement of Basicity,
    : > if you want to
    : > > get picky, which seems you do.
    : > >
    : > >
    : > > "How do you remove CO2? "
    : > >
    : > > It is called "blowing it off" , such as with an airstone. If you have
    : high
    : > CO2 and add an
    : > > airstone it will drive the CO2 off raising the pH. It can be proven with
    : a
    : > glass of water,
    : > > a straw, some pH color indicator and an Alk test kit and if you must a
    : CO2
    : > test kit
    : > >
    : > > >You can have all the alk you want in the world and it won't help, in
    : > > regards to CO2
    : > >
    : > > "Wrong. Alkalinity increases your tank's ability to RESIST sharp
    : changes
    : > in
    : > > pH. This is what is meant by 'buffering capacity'"
    : > >
    : > > No you are wrong and very lost. If Alk resists changes in pH then why
    : does
    : > CO2 lower the
    : > > pH without affecting the Alk ? CO2 has no effect on alk and alk has no
    : > effect on CO2. When
    : > > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At any
    : > pH no matter what
    : > > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    : > >
    : > > .
    : > > Go ahead and pick a seawater pH and I will tell you what that ratio is.
    : > Tell me the pH and
    : > > Alk and I will give the CO2 concentration. Give me the Alk and CO2 and
    : I
    : > will give you
    : > > the pH. Don't forget the temperature and Salinity.
    : > >
    : > > Alk is defined as;
    : > >
    : > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : > [HPO4--] +
    : > > 2[PO4---] - [H+]
    : > >
    : > >
    : > > Buffering Capacity is defined as;
    : > >
    : > > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka + [H3O+])²
    : > >
    : > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > maximum BC is at a
    : > > pH of 6 & 9. For all practically purposes seawater has very little
    : > Buffering Capacity, if
    : > > any at all.
    : > >
    : > >
    : > > Alkalinity and Buffer Capacity are closely tied but are NOT the same
    : > thing, it is a
    : > > misunderstanding and use of the term. Do you think water chemistry books
    : > would have
    : > > separate sections on Alkalinity and Buffering Capacity if they were the
    : > same thing ?
    : > >
    : > > By the way do you know who you are talking to ?
    : > >
    : > > --
    : > > Boomer
    : > >
    : > > Want to talk chemistry ? The Reef Chemistry Forum
    : > > http://www.reefcentral.com/vbulletin/index.php
    : > >
    : > > Want to See More ?
    : > > Please Join Our Growing Membership
    : > > www.coralrealm.com
    : > >
    : > > If You See Me Running You Better Catch-Up
    : > >
    : > >
    : >
    : >
    :
    :
     
    Boomer, Feb 9, 2004
    #17
  18. Dinky

    Boomer Guest

    I don't care about credentials, they are meaningless, it is what is the answer and the
    merit of the answer, credentials or not.

    --
    Boomer

    Want to talk chemistry ? The Reef Chemistry Forum
    http://www.reefcentral.com/vbulletin/index.php

    Want to See More ?
    Please Join Our Growing Membership
    www.coralrealm.com

    If You See Me Running You Better Catch-Up
    "stoutman" <.@.> wrote in message news:YeOVb.204890$Rc4.1682472@attbi_s54...
    : If you knew my credentials you would laugh at yourself.
    :
    :
    : "Dragon Slayer" <koi_man@nospam_hotmail.com> wrote in message
    : news:c08a79$86iq$1@news3.infoave.net...
    : > Boomer when you read that, just let it go.............no need bashing
    : heads
    : > here, the group knows what's going on.
    : >
    : > kc
    : >
    : > "stoutman" <.@.> wrote in message
    : news:SFNVb.204571$Rc4.1681932@attbi_s54...
    : > > Oh brother. Where to start.
    : > >
    : > > pH is the -log of the hydronium ion concentration. When the hydronium
    : ion
    : > > concentration is very low, your system is basic (high pH). When the
    : > > hydronium ion concentration is very large, your system is acidic (low
    : pH).
    : > >
    : > > pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice
    : versa.
    : > > But a pH of < 7 means acidic. pH > 7 means basic.
    : > > pH can tell you something about acidity and basicity. It is a
    : measurement
    : > > of both, or the entire pH scale (1-14) if you will.
    : > >
    : > > >It is called "blowing it off" , such as with an airstone. If you have
    : > high
    : > > CO2 and add an airstone it will drive the CO2 off raising the pH.
    : > >
    : > > Ok, you are going to try and 'purge' (the correct term) your CO2 out
    : with
    : > > air. Yeah, I guess that would work. If you intentionally put the CO2
    : in
    : > > there to begin with because you must have a higher concentration of CO2
    : in
    : > > your tank than in the atmosphere. I don't intentionally put CO2 in my
    : > tank.
    : > > But I know some of you reef people due in Kalk reactors.
    : > >
    : > > >If Alk resists changes in pH then why does CO2 lower the pH without
    : > > affecting the Alk.
    : > >
    : > > Alkalinity is buffering capacity. Your buffers begin to get weakened
    : with
    : > > the addition of acid until they reach a point when they can no longer
    : > > 'buffer' and the pH crashes.
    : > >
    : > > >But I know what you mean, may use the term ALK and BC interchangeably
    : > >
    : > > Do you remember writing this in an earlier post? If you believe that
    : > > alkalinity and buffering capacity can be used interchangeably than I
    : must
    : > be
    : > > getting through to you.
    : > >
    : > > >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3.
    : At
    : > > any pH no matter what the Alk or CO2 there will be an exact ratio of
    : > > CO2:HCO3:CO3
    : > >
    : > > Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is
    : > your
    : > > point here?
    : > >
    : > > > Go ahead and pick a seawater pH and I will tell you what that ratio
    : is.
    : > > Tell me the pH and
    : > > > Alk and I will give the CO2 concentration. Give me the Alk and CO2
    : and
    : > I
    : > > will give you
    : > > > the pH. Don't forget the temperature and Salinity.
    : > >
    : > > Not interested. I can find my own software to do this too.
    : > >
    : > > > Alk is defined as;
    : > > >
    : > > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : > > [HPO4--] +
    : > > > 2[PO4---] - [H+]
    : > >
    : > > Ahh, now we are getting somewhere. What you are showing are components
    : of
    : > a
    : > > 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    : > > going in circles here? Anyway, I think you are learning something.
    : > >
    : > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > > maximum BC is at a
    : > > > pH of 6 & 9. For all practically purposes seawater has very little
    : > > Buffering Capacity, if
    : > > > any at all.
    : > >
    : > > This is the 'primary buffer' in sea water:
    : > >
    : > > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    : > >
    : > > If you REALLY believe that sea water has little buffering capacity, than
    : > you
    : > > need to do some reading on your own. I wont be able to convince you.
    : > >
    : > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > > maximum BC is at a
    : > > > pH of 6 & 9. For all practically purposes seawater has very little
    : > > Buffering Capacity, if
    : > > > any at all.
    : > >
    : > > This would be true if a monoprotic acid where used in the 'buffer', but
    : > > carbonic acid (the primary buffering component in seawater) is a
    : > polyprotic
    : > > acid. It has two protons that can dissociate. Therefore, it has two
    : > pKa's
    : > > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.
    : > The
    : > > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    : > > right in there. Is that magic? :)
    : > >
    : > > Remember that seawater is more than a mixture of just carbonate and CO2,
    : > > there are other buffers involved that make it even more complicated I'm
    : > > sure.
    : > >
    : > > > By the way do you know who you are talking to ?
    : > >
    : > > No. Do you?
    : > >
    : > >
    : > >
    : > >
    : > > "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    : > > news:102edca3c38a643@corp.supernews.com...
    : > > > Let me make this clear you don't know what you are taking about
    : > > >
    : > > > "alkalinity is a measurement of 'buffering capacity'"
    : > > >
    : > > > No, it is the ability to neutralize an acid. BC is the ability to
    : > > withstand both upward
    : > > > and downward trends in pH.
    : > > >
    : > > > "pH is a measurement of 'acidity/basicity'.
    : > > >
    : > > > No, pH is a measurement of acidity and pOH is a measurement of
    : Basicity,
    : > > if you want to
    : > > > get picky, which seems you do.
    : > > >
    : > > >
    : > > > "How do you remove CO2? "
    : > > >
    : > > > It is called "blowing it off" , such as with an airstone. If you have
    : > high
    : > > CO2 and add an
    : > > > airstone it will drive the CO2 off raising the pH. It can be proven
    : with
    : > a
    : > > glass of water,
    : > > > a straw, some pH color indicator and an Alk test kit and if you must a
    : > CO2
    : > > test kit
    : > > >
    : > > > >You can have all the alk you want in the world and it won't help, in
    : > > > regards to CO2
    : > > >
    : > > > "Wrong. Alkalinity increases your tank's ability to RESIST sharp
    : > changes
    : > > in
    : > > > pH. This is what is meant by 'buffering capacity'"
    : > > >
    : > > > No you are wrong and very lost. If Alk resists changes in pH then why
    : > does
    : > > CO2 lower the
    : > > > pH without affecting the Alk ? CO2 has no effect on alk and alk has no
    : > > effect on CO2. When
    : > > > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At
    : any
    : > > pH no matter what
    : > > > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    : > > >
    : > > > .
    : > > > Go ahead and pick a seawater pH and I will tell you what that ratio
    : is.
    : > > Tell me the pH and
    : > > > Alk and I will give the CO2 concentration. Give me the Alk and CO2
    : and
    : > I
    : > > will give you
    : > > > the pH. Don't forget the temperature and Salinity.
    : > > >
    : > > > Alk is defined as;
    : > > >
    : > > > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    : > > [HPO4--] +
    : > > > 2[PO4---] - [H+]
    : > > >
    : > > >
    : > > > Buffering Capacity is defined as;
    : > > >
    : > > > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka +
    : [H3O+])²
    : > > >
    : > > > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    : > > maximum BC is at a
    : > > > pH of 6 & 9. For all practically purposes seawater has very little
    : > > Buffering Capacity, if
    : > > > any at all.
    : > > >
    : > > >
    : > > > Alkalinity and Buffer Capacity are closely tied but are NOT the same
    : > > thing, it is a
    : > > > misunderstanding and use of the term. Do you think water chemistry
    : books
    : > > would have
    : > > > separate sections on Alkalinity and Buffering Capacity if they were
    : the
    : > > same thing ?
    : > > >
    : > > > By the way do you know who you are talking to ?
    : > > >
    : > > > --
    : > > > Boomer
    : > > >
    : > > > Want to talk chemistry ? The Reef Chemistry Forum
    : > > > http://www.reefcentral.com/vbulletin/index.php
    : > > >
    : > > > Want to See More ?
    : > > > Please Join Our Growing Membership
    : > > > www.coralrealm.com
    : > > >
    : > > > If You See Me Running You Better Catch-Up
    : > > >
    : > > >
    : > >
    : > >
    : >
    : >
    :
    :
     
    Boomer, Feb 9, 2004
    #18
  19. Dinky

    stoutman Guest

    >Alkalinity only deals with downward trends and says nothing of upward
    trends. Ever hear of an Acidity test kit ?

    Downwards trends of what? Acidity? Basicity? Have I ever heard of an
    acidity test? Yeah, it's called pH paper. or a pH meter.

    > As far as primary "buffers" in seawater you are lost again. The principle

    buffers of seawater are HCO3, CO3.

    Ever heard of the Henderson-Hasselbach equation?

    pH = pKa + log [HA]/[A-]

    The pKa of CO3-2 is 10.3. Thus, at a pH of 8.3 (seawater for this example)
    you would have a 1 : 100 ratio of CO3-2 and HCO3-2. The equilibrium will
    be shifted to HCO3-2 by a ratio of 1:100.

    8.3 = 10.3 + log [HCO3-2]/[CO3-2]
    -2 = log [HCO3-2]/[CO3-2]

    take antilog of both sides and you get:

    ..01 = [HCO3-2]/[CO3-2]

    Therefore, at a pH of 8.3 (seawater for this example) the majority of
    carbonate in solution exists as HCO3-2 not CO3-2. That is why I did not
    include it in my buffer example.

    You said:
    >The principle buffers of seawater are HCO3, CO3 and B(OH4).


    and You said in a previous post:

    >For all practically purposes seawater has very little Buffering Capacity,

    if any at all.

    STOP contradicting yourself, you are confusing the matter for yourself and
    others. How can HCO3, CO3 and B(OH4) be buffers in seawater if "For all
    practically purposes seawater has very little Buffering Capacity" AND if
    "About 1/3 of seawaters Buffer Capacity is due to MgCO3" ?????

    You are saying seawater has no buffering capacity and you are saying 1/3 of
    seawaters Buffer Capacity is due to MgCO3 ??

    Are you on drugs? Just kidding. I just want to help you understand.

    Can I make a suggestion for you? Stop getting your chemistry knowledge from
    aquarium books. Most are written by Marine Biologists, not CHEMISTS, like
    myself. I have seen NUMEROUS chemistry flaws in aquarium books. This is
    why this topic so muddied.

    > It does work it is not a maybe. Intentionally !!!!! where are you coming

    from or where
    > have you been ??? CO2 is produced by normal biological activity and is the

    reason behind
    > many low pH's in tanks, as is room air CO2


    Oh, man. Interesting. Here is another contradiction of yours. You said
    before you purge CO2 from your tank with air to raise the pH. Here you are
    telling me that CO2 from air is the reason behind many low pH's.


    > pKa1 = 6.0 pKa2 = 9.1
    > From Introduction to Marine Chemistry by Riley and Chester. Also from, An

    Introduction to the Chemistry of the Sea, by Pilson

    STOP GETTING YOUR CHEMISTRY FROM AQUARIUM BOOKS. Get a CHEMISTRY book.

    > Well go get some, as you need it, that is for sure.


    Not likely.







    "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    news:102fgodnu9ahu22@corp.supernews.com...
    > <Alkalinity is buffering capacity. >
    >
    > No it is not, they are not calculated the same. I already gave the

    equations please, you
    > seem to avoiding them. Please consult an aquatic chemistry book.
    >
    > ">But I know what you mean, many use the term ALK and BC interchangeably"
    >
    > Yes, I most certainly do and stated it is incorrect but I know what you

    mean
    >
    >
    > <If you believe that
    > alkalinity and buffering capacity can be used interchangeably than I must

    be
    > getting through to you.>
    >
    > Please don't make me laugh. No I'm not getting through
    >
    >
    > <Which are used in the over all 'buffering capacity'. Are we
    > going in circles here? Anyway, I think you are learning something>
    >
    > No I'm not learning anything but you need to. No I'm not talking in a

    circle but maybe you
    > are. You must have missed it, so here it is again. Buffer capacity is the

    ability to with
    > stand upward & downward trends in pH. Alkalinity only deals with downward

    trends and says
    > nothing of upward trends. Ever hear of an Acidity test kit ?
    >
    > <This is the 'primary buffer' in sea water:>
    >
    > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1"
    >
    > You are lost, the reaction that it is inherent to is;........... and you

    are missing some
    > things
    >
    > 2HCO3 <--->CO2 + H20 + ***CO3***
    >
    >
    > As far as primary "buffers" in seawater you are lost again. The principle

    buffers of
    > seawater are HCO3, CO3 and
    > B(OH4). I might add that Ion pairs are also part of the Buffer Capacity.

    About 1/3 of
    > seawaters Buffer Capacity is due to MgCO3. Like I said you don't

    understand Buffer
    > Capacity and Alkalinity. Seawater manuals and text books are filled with

    this kind of
    > data.Would you like me to give a list of some ?? :)
    >
    > "If you REALLY believe that sea water has little buffering capacity, than

    you
    > need to do some reading on your own. I wont be able to convince you."
    >
    > It doesn't if you understand the issue and it is quite clear you don't.

    You are the one
    > that need to do allllllllllllot of reading
    >
    > ***For terms are commonly used to describe various aspects of the seawater

    buffer system:
    >
    > 1.pH
    >
    > 2. Buffering Capacity
    >
    > 3. Alkalinity or Total Alkalinity
    >
    > 4. Carbonate Alkalinity***
    >
    > From;
    > Spotte, Seawater Aquariums the Captive Environment ( a technical text book

    on seawater and
    > seawater aquariums)
    >
    >
    > ***In seawater, for example, maximum Buffering Capacity appears at pH

    values near 6 and 9
    > and seawater is buffered very little , if at all, at its normal pH of

    8.2***
    >
    > From;
    > Skirrow, 1975 Chemical Oceanography Vol 2
    >
    > <but
    > carbonic acid (the primary buffering component in seawater) >
    >
    > Bicarbonate is the primary buffer not carbonic acid ,where on God's earth

    did you get that
    > from. At normal temp, salinity, pH and Alk it is;
    >
    > @ 20C and 34.3 ppt salinity
    >
    > CO2 = 0.52 %
    >
    > HCO3 = 86.4 %
    >
    > CO3 = 13.09 %
    >
    > From;
    > Practical Handbook of Marine Science, M.J. Kennish
    >
    > <Therefore, it has two pKa's
    > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > right in there. Is that magic? :)>
    >
    > Magic !!!! it must be by your account. That is FW there pal, not

    seawater, lets get the
    > water straight here that we are dealing with, so you aren't so lost.
    >
    > The;
    > pKa1 = 6.0
    >
    > pKa2 = 9.1
    >
    > From;
    > Introduction to Marine Chemistry by Riley and Chester. Also from, An

    Introduction to the
    > Chemistry of the Sea, by Pilson
    >
    > So your equation does not work as you gave it.
    >
    > (6.0 + 9.1) / 2 = 7.55 pH Hum, maybe you would care to explain that

    since you seem to
    > think you have all the answers.
    >
    > <Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > point here?>
    >
    > It means that if the pH is 8.3 and the Alk is 4.0 meq/ l or if the is pH

    8.3 and the Alk
    > 1.5 Meq /l, or no mater what the Alk level is, if the pH is the same, the

    ratio's of CO2
    > to HCO3 to CO3 will be the same. So you are not lost here :)
    >
    > pH = 8.2
    >
    > Alk = 4.0 meq /l
    >
    > or
    >
    > pH = *.2
    >
    > Alk = 1.5 meq /
    >
    > The percentage or ratio is still the same for both, both will be . 0.52%

    CO2, 86.4 % HCO3
    > and 13.09 % @ 34.3 ppt and @ 20 C
    >
    > <Yeah, I guess that would work. If you intentionally put the CO2 in
    > there to begin with because you must have a higher concentration of CO2 in
    > your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank>
    >
    > It does work it is not a maybe. Intentionally !!!!! where are you coming

    from or where
    > have you been ??? CO2 is produced by normal biological activity and is the

    resaon behind
    > many low pH's in tanks, as is room air CO2
    >
    > <you must have a higher concentration of CO2 in
    > your tank than in the atmosphere>
    >
    > What !!! CO2 does not have to be higher than ambient air .Quite often CO2

    is produced in
    > the water and can't leave fast enough, has one would normally expect , by

    simple diffusion
    > to the atmosphere. It is the reason why CO2 can get so high in almost any

    aquatic system
    > and is the same reason CO2 can get so low. Why do you think Planted FW

    Aquarium guys use
    > CO2 injection ? As the plants can remove the CO2 faster than it can

    diffuse across the
    > water air interface. Same for a FOT, the CO2 can accumulate faster than it

    can diffuse,
    > thus crashing the pH
    >
    > <Not interested. I can find my own software to do this too.>
    >
    > Well go get some, as you need it, that is for sure.
    > --
    > Boomer
    >
    > Want to talk chemistry ? The Reef Chemistry Forum
    > http://www.reefcentral.com/vbulletin/index.php
    >
    > Want to See More ?
    > Please Join Our Growing Membership
    > www.coralrealm.com
    >
    > If You See Me Running You Better Catch-Up
    > "stoutman" <.@.> wrote in message

    news:SFNVb.204571$Rc4.1681932@attbi_s54...
    > : Oh brother. Where to start.
    > :
    > : pH is the -log of the hydronium ion concentration. When the hydronium

    ion
    > : concentration is very low, your system is basic (high pH). When the
    > : hydronium ion concentration is very large, your system is acidic (low

    pH).
    > :
    > : pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice

    versa.
    > : But a pH of < 7 means acidic. pH > 7 means basic.
    > : pH can tell you something about acidity and basicity. It is a

    measurement
    > : of both, or the entire pH scale (1-14) if you will.
    > :
    > : >It is called "blowing it off" , such as with an airstone. If you have

    high
    > : CO2 and add an airstone it will drive the CO2 off raising the pH.
    > :
    > : Ok, you are going to try and 'purge' (the correct term) your CO2 out

    with
    > : air. Yeah, I guess that would work. If you intentionally put the CO2

    in
    > : there to begin with because you must have a higher concentration of CO2

    in
    > : your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank.
    > : But I know some of you reef people due in Kalk reactors.
    > :
    > : >If Alk resists changes in pH then why does CO2 lower the pH without
    > : affecting the Alk.
    > :
    > : Alkalinity is buffering capacity. Your buffers begin to get weakened

    with
    > : the addition of acid until they reach a point when they can no longer
    > : 'buffer' and the pH crashes.
    > :
    > : >But I know what you mean, may use the term ALK and BC interchangeably
    > :
    > : Do you remember writing this in an earlier post? If you believe that
    > : alkalinity and buffering capacity can be used interchangeably than I

    must be
    > : getting through to you.
    > :
    > : >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3.

    At
    > : any pH no matter what the Alk or CO2 there will be an exact ratio of
    > : CO2:HCO3:CO3
    > :
    > : Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > : point here?
    > :
    > : > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > : Tell me the pH and
    > : > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and I
    > : will give you
    > : > the pH. Don't forget the temperature and Salinity.
    > :
    > : Not interested. I can find my own software to do this too.
    > :
    > : > Alk is defined as;
    > : >
    > : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    > : [HPO4--] +
    > : > 2[PO4---] - [H+]
    > :
    > : Ahh, now we are getting somewhere. What you are showing are components

    of a
    > : 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    > : going in circles here? Anyway, I think you are learning something.
    > :
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > :
    > : This is the 'primary buffer' in sea water:
    > :
    > : H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    > :
    > : If you REALLY believe that sea water has little buffering capacity, than

    you
    > : need to do some reading on your own. I wont be able to convince you.
    > :
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > :
    > : This would be true if a monoprotic acid where used in the 'buffer', but
    > : carbonic acid (the primary buffering component in seawater) is a

    polyprotic
    > : acid. It has two protons that can dissociate. Therefore, it has two

    pKa's
    > : (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > : pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > : right in there. Is that magic? :)
    > :
    > : Remember that seawater is more than a mixture of just carbonate and CO2,
    > : there are other buffers involved that make it even more complicated I'm
    > : sure.
    > :
    > : > By the way do you know who you are talking to ?
    > :
    > : No. Do you?
    > :
    > :
    > :
    > :
    > : "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    > : news:102edca3c38a643@corp.supernews.com...
    > : > Let me make this clear you don't know what you are taking about
    > : >
    > : > "alkalinity is a measurement of 'buffering capacity'"
    > : >
    > : > No, it is the ability to neutralize an acid. BC is the ability to
    > : withstand both upward
    > : > and downward trends in pH.
    > : >
    > : > "pH is a measurement of 'acidity/basicity'.
    > : >
    > : > No, pH is a measurement of acidity and pOH is a measurement of

    Basicity,
    > : if you want to
    > : > get picky, which seems you do.
    > : >
    > : >
    > : > "How do you remove CO2? "
    > : >
    > : > It is called "blowing it off" , such as with an airstone. If you have

    high
    > : CO2 and add an
    > : > airstone it will drive the CO2 off raising the pH. It can be proven

    with a
    > : glass of water,
    > : > a straw, some pH color indicator and an Alk test kit and if you must a

    CO2
    > : test kit
    > : >
    > : > >You can have all the alk you want in the world and it won't help, in
    > : > regards to CO2
    > : >
    > : > "Wrong. Alkalinity increases your tank's ability to RESIST sharp

    changes
    > : in
    > : > pH. This is what is meant by 'buffering capacity'"
    > : >
    > : > No you are wrong and very lost. If Alk resists changes in pH then why

    does
    > : CO2 lower the
    > : > pH without affecting the Alk ? CO2 has no effect on alk and alk has no
    > : effect on CO2. When
    > : > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    any
    > : pH no matter what
    > : > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    > : >
    > : > .
    > : > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > : Tell me the pH and
    > : > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and I
    > : will give you
    > : > the pH. Don't forget the temperature and Salinity.
    > : >
    > : > Alk is defined as;
    > : >
    > : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    > : [HPO4--] +
    > : > 2[PO4---] - [H+]
    > : >
    > : >
    > : > Buffering Capacity is defined as;
    > : >
    > : > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka +

    [H3O+])²
    > : >
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > : >
    > : >
    > : > Alkalinity and Buffer Capacity are closely tied but are NOT the same
    > : thing, it is a
    > : > misunderstanding and use of the term. Do you think water chemistry

    books
    > : would have
    > : > separate sections on Alkalinity and Buffering Capacity if they were

    the
    > : same thing ?
    > : >
    > : > By the way do you know who you are talking to ?
    > : >
    > : > --
    > : > Boomer
    > : >
    > : > Want to talk chemistry ? The Reef Chemistry Forum
    > : > http://www.reefcentral.com/vbulletin/index.php
    > : >
    > : > Want to See More ?
    > : > Please Join Our Growing Membership
    > : > www.coralrealm.com
    > : >
    > : > If You See Me Running You Better Catch-Up
    > : >
    > : >
    > :
    > :
    >
    >
     
    stoutman, Feb 9, 2004
    #19
  20. Dinky

    stoutman Guest

    >Alkalinity only deals with downward trends and says nothing of upward
    trends. Ever hear of an Acidity test kit ?

    Downwards trends of what? Acidity? Basicity? Have I ever heard of an
    acidity test? Yeah, it's called pH paper. or a pH meter.

    > As far as primary "buffers" in seawater you are lost again. The principle

    buffers of seawater are HCO3, CO3.

    Ever heard of the Henderson-Hasselbach equation?

    pH = pKa + log [A-]/[HA]

    The pKa of CO3-2 is 10.3. Thus, at a pH of 8.3 (seawater for this example)
    you would have a 1 : 100 ratio of CO3-2 and HCO3-2. The equilibrium will
    be shifted to HCO3-2 by a ratio of 1:100.

    8.3 = 10.3 + log [HCO3-2]/[CO3-2]
    -2 = log [HCO3-2]/[CO3-2]

    take antilog of both sides and you get:

    ..01 = [HCO3-2]/[CO3-2]

    Therefore, at a pH of 8.3 (seawater for this example) the majority of
    carbonate in solution exists as HCO3-2 not CO3-2. That is why I did not
    include it in my buffer example.

    You said:
    >The principle buffers of seawater are HCO3, CO3 and B(OH4).


    and You said in a previous post:

    >For all practically purposes seawater has very little Buffering Capacity,

    if any at all.

    STOP contradicting yourself, you are confusing the matter for yourself and
    others. How can HCO3, CO3 and B(OH4) be buffers in seawater if "For all
    practically purposes seawater has very little Buffering Capacity" AND if
    "About 1/3 of seawaters Buffer Capacity is due to MgCO3" ?????

    You are saying seawater has no buffering capacity and you are saying 1/3 of
    seawaters Buffer Capacity is due to MgCO3 ??

    Are you on drugs? Just kidding. I just want to help you understand.

    Can I make a suggestion for you? Stop getting your chemistry knowledge from
    aquarium books. Most are written by Marine Biologists, not CHEMISTS, like
    myself. I have seen NUMEROUS chemistry flaws in aquarium books. This is
    why this topic so muddied.

    > It does work it is not a maybe. Intentionally !!!!! where are you coming

    from or where
    > have you been ??? CO2 is produced by normal biological activity and is the

    reason behind
    > many low pH's in tanks, as is room air CO2


    Oh, man. Interesting. Here is another contradiction of yours. You said
    before you purge CO2 from your tank with air to raise the pH. Here you are
    telling me that CO2 from air is the reason behind many low pH's.


    > pKa1 = 6.0 pKa2 = 9.1
    > From Introduction to Marine Chemistry by Riley and Chester. Also from, An

    Introduction to the Chemistry of the Sea, by Pilson

    STOP GETTING YOUR CHEMISTRY FROM AQUARIUM BOOKS. Get a CHEMISTRY book.

    > Well go get some, as you need it, that is for sure.


    Not likely.










    "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    news:102fgodnu9ahu22@corp.supernews.com...
    > <Alkalinity is buffering capacity. >
    >
    > No it is not, they are not calculated the same. I already gave the

    equations please, you
    > seem to avoiding them. Please consult an aquatic chemistry book.
    >
    > ">But I know what you mean, many use the term ALK and BC interchangeably"
    >
    > Yes, I most certainly do and stated it is incorrect but I know what you

    mean
    >
    >
    > <If you believe that
    > alkalinity and buffering capacity can be used interchangeably than I must

    be
    > getting through to you.>
    >
    > Please don't make me laugh. No I'm not getting through
    >
    >
    > <Which are used in the over all 'buffering capacity'. Are we
    > going in circles here? Anyway, I think you are learning something>
    >
    > No I'm not learning anything but you need to. No I'm not talking in a

    circle but maybe you
    > are. You must have missed it, so here it is again. Buffer capacity is the

    ability to with
    > stand upward & downward trends in pH. Alkalinity only deals with downward

    trends and says
    > nothing of upward trends. Ever hear of an Acidity test kit ?
    >
    > <This is the 'primary buffer' in sea water:>
    >
    > H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1"
    >
    > You are lost, the reaction that it is inherent to is;........... and you

    are missing some
    > things
    >
    > 2HCO3 <--->CO2 + H20 + ***CO3***
    >
    >
    > As far as primary "buffers" in seawater you are lost again. The principle

    buffers of
    > seawater are HCO3, CO3 and
    > B(OH4). I might add that Ion pairs are also part of the Buffer Capacity.

    About 1/3 of
    > seawaters Buffer Capacity is due to MgCO3. Like I said you don't

    understand Buffer
    > Capacity and Alkalinity. Seawater manuals and text books are filled with

    this kind of
    > data.Would you like me to give a list of some ?? :)
    >
    > "If you REALLY believe that sea water has little buffering capacity, than

    you
    > need to do some reading on your own. I wont be able to convince you."
    >
    > It doesn't if you understand the issue and it is quite clear you don't.

    You are the one
    > that need to do allllllllllllot of reading
    >
    > ***For terms are commonly used to describe various aspects of the seawater

    buffer system:
    >
    > 1.pH
    >
    > 2. Buffering Capacity
    >
    > 3. Alkalinity or Total Alkalinity
    >
    > 4. Carbonate Alkalinity***
    >
    > From;
    > Spotte, Seawater Aquariums the Captive Environment ( a technical text book

    on seawater and
    > seawater aquariums)
    >
    >
    > ***In seawater, for example, maximum Buffering Capacity appears at pH

    values near 6 and 9
    > and seawater is buffered very little , if at all, at its normal pH of

    8.2***
    >
    > From;
    > Skirrow, 1975 Chemical Oceanography Vol 2
    >
    > <but
    > carbonic acid (the primary buffering component in seawater) >
    >
    > Bicarbonate is the primary buffer not carbonic acid ,where on God's earth

    did you get that
    > from. At normal temp, salinity, pH and Alk it is;
    >
    > @ 20C and 34.3 ppt salinity
    >
    > CO2 = 0.52 %
    >
    > HCO3 = 86.4 %
    >
    > CO3 = 13.09 %
    >
    > From;
    > Practical Handbook of Marine Science, M.J. Kennish
    >
    > <Therefore, it has two pKa's
    > (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > right in there. Is that magic? :)>
    >
    > Magic !!!! it must be by your account. That is FW there pal, not

    seawater, lets get the
    > water straight here that we are dealing with, so you aren't so lost.
    >
    > The;
    > pKa1 = 6.0
    >
    > pKa2 = 9.1
    >
    > From;
    > Introduction to Marine Chemistry by Riley and Chester. Also from, An

    Introduction to the
    > Chemistry of the Sea, by Pilson
    >
    > So your equation does not work as you gave it.
    >
    > (6.0 + 9.1) / 2 = 7.55 pH Hum, maybe you would care to explain that

    since you seem to
    > think you have all the answers.
    >
    > <Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > point here?>
    >
    > It means that if the pH is 8.3 and the Alk is 4.0 meq/ l or if the is pH

    8.3 and the Alk
    > 1.5 Meq /l, or no mater what the Alk level is, if the pH is the same, the

    ratio's of CO2
    > to HCO3 to CO3 will be the same. So you are not lost here :)
    >
    > pH = 8.2
    >
    > Alk = 4.0 meq /l
    >
    > or
    >
    > pH = *.2
    >
    > Alk = 1.5 meq /
    >
    > The percentage or ratio is still the same for both, both will be . 0.52%

    CO2, 86.4 % HCO3
    > and 13.09 % @ 34.3 ppt and @ 20 C
    >
    > <Yeah, I guess that would work. If you intentionally put the CO2 in
    > there to begin with because you must have a higher concentration of CO2 in
    > your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank>
    >
    > It does work it is not a maybe. Intentionally !!!!! where are you coming

    from or where
    > have you been ??? CO2 is produced by normal biological activity and is the

    resaon behind
    > many low pH's in tanks, as is room air CO2
    >
    > <you must have a higher concentration of CO2 in
    > your tank than in the atmosphere>
    >
    > What !!! CO2 does not have to be higher than ambient air .Quite often CO2

    is produced in
    > the water and can't leave fast enough, has one would normally expect , by

    simple diffusion
    > to the atmosphere. It is the reason why CO2 can get so high in almost any

    aquatic system
    > and is the same reason CO2 can get so low. Why do you think Planted FW

    Aquarium guys use
    > CO2 injection ? As the plants can remove the CO2 faster than it can

    diffuse across the
    > water air interface. Same for a FOT, the CO2 can accumulate faster than it

    can diffuse,
    > thus crashing the pH
    >
    > <Not interested. I can find my own software to do this too.>
    >
    > Well go get some, as you need it, that is for sure.
    > --
    > Boomer
    >
    > Want to talk chemistry ? The Reef Chemistry Forum
    > http://www.reefcentral.com/vbulletin/index.php
    >
    > Want to See More ?
    > Please Join Our Growing Membership
    > www.coralrealm.com
    >
    > If You See Me Running You Better Catch-Up
    > "stoutman" <.@.> wrote in message

    news:SFNVb.204571$Rc4.1681932@attbi_s54...
    > : Oh brother. Where to start.
    > :
    > : pH is the -log of the hydronium ion concentration. When the hydronium

    ion
    > : concentration is very low, your system is basic (high pH). When the
    > : hydronium ion concentration is very large, your system is acidic (low

    pH).
    > :
    > : pH + pOH = 14. So yeah, you can calculate a pH from a pOH and vice

    versa.
    > : But a pH of < 7 means acidic. pH > 7 means basic.
    > : pH can tell you something about acidity and basicity. It is a

    measurement
    > : of both, or the entire pH scale (1-14) if you will.
    > :
    > : >It is called "blowing it off" , such as with an airstone. If you have

    high
    > : CO2 and add an airstone it will drive the CO2 off raising the pH.
    > :
    > : Ok, you are going to try and 'purge' (the correct term) your CO2 out

    with
    > : air. Yeah, I guess that would work. If you intentionally put the CO2

    in
    > : there to begin with because you must have a higher concentration of CO2

    in
    > : your tank than in the atmosphere. I don't intentionally put CO2 in my

    tank.
    > : But I know some of you reef people due in Kalk reactors.
    > :
    > : >If Alk resists changes in pH then why does CO2 lower the pH without
    > : affecting the Alk.
    > :
    > : Alkalinity is buffering capacity. Your buffers begin to get weakened

    with
    > : the addition of acid until they reach a point when they can no longer
    > : 'buffer' and the pH crashes.
    > :
    > : >But I know what you mean, may use the term ALK and BC interchangeably
    > :
    > : Do you remember writing this in an earlier post? If you believe that
    > : alkalinity and buffering capacity can be used interchangeably than I

    must be
    > : getting through to you.
    > :
    > : >When CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3.

    At
    > : any pH no matter what the Alk or CO2 there will be an exact ratio of
    > : CO2:HCO3:CO3
    > :
    > : Yes, at any pH there will be 'SOME' ratio of CO2:HCO3-1:CO3-2. What is

    your
    > : point here?
    > :
    > : > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > : Tell me the pH and
    > : > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and I
    > : will give you
    > : > the pH. Don't forget the temperature and Salinity.
    > :
    > : Not interested. I can find my own software to do this too.
    > :
    > : > Alk is defined as;
    > : >
    > : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    > : [HPO4--] +
    > : > 2[PO4---] - [H+]
    > :
    > : Ahh, now we are getting somewhere. What you are showing are components

    of a
    > : 'BUFFER'. Which are used in the over all 'buffering capacity'. Are we
    > : going in circles here? Anyway, I think you are learning something.
    > :
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > :
    > : This is the 'primary buffer' in sea water:
    > :
    > : H2O + CO2 <---> H2CO3 <---> H+ + HCO3-1
    > :
    > : If you REALLY believe that sea water has little buffering capacity, than

    you
    > : need to do some reading on your own. I wont be able to convince you.
    > :
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > :
    > : This would be true if a monoprotic acid where used in the 'buffer', but
    > : carbonic acid (the primary buffering component in seawater) is a

    polyprotic
    > : acid. It has two protons that can dissociate. Therefore, it has two

    pKa's
    > : (pKa1 and pKa2). pH = (pKa1 + pKa2)/2 pH = (6.4 + 10.3)/2 pH = 8.35.

    The
    > : pH of seawater varies from 7.6 to 8.4. Hmmm. That pH I calculated is
    > : right in there. Is that magic? :)
    > :
    > : Remember that seawater is more than a mixture of just carbonate and CO2,
    > : there are other buffers involved that make it even more complicated I'm
    > : sure.
    > :
    > : > By the way do you know who you are talking to ?
    > :
    > : No. Do you?
    > :
    > :
    > :
    > :
    > : "Boomer" <wcwing_nospam_@chartermi.net> wrote in message
    > : news:102edca3c38a643@corp.supernews.com...
    > : > Let me make this clear you don't know what you are taking about
    > : >
    > : > "alkalinity is a measurement of 'buffering capacity'"
    > : >
    > : > No, it is the ability to neutralize an acid. BC is the ability to
    > : withstand both upward
    > : > and downward trends in pH.
    > : >
    > : > "pH is a measurement of 'acidity/basicity'.
    > : >
    > : > No, pH is a measurement of acidity and pOH is a measurement of

    Basicity,
    > : if you want to
    > : > get picky, which seems you do.
    > : >
    > : >
    > : > "How do you remove CO2? "
    > : >
    > : > It is called "blowing it off" , such as with an airstone. If you have

    high
    > : CO2 and add an
    > : > airstone it will drive the CO2 off raising the pH. It can be proven

    with a
    > : glass of water,
    > : > a straw, some pH color indicator and an Alk test kit and if you must a

    CO2
    > : test kit
    > : >
    > : > >You can have all the alk you want in the world and it won't help, in
    > : > regards to CO2
    > : >
    > : > "Wrong. Alkalinity increases your tank's ability to RESIST sharp

    changes
    > : in
    > : > pH. This is what is meant by 'buffering capacity'"
    > : >
    > : > No you are wrong and very lost. If Alk resists changes in pH then why

    does
    > : CO2 lower the
    > : > pH without affecting the Alk ? CO2 has no effect on alk and alk has no
    > : effect on CO2. When
    > : > CO2 is added or remove it just changes the ratio of CO2:HCO3:CO3. At

    any
    > : pH no matter what
    > : > the Alk or CO2 there will be an exact ratio of CO2:HCO3:CO3
    > : >
    > : > .
    > : > Go ahead and pick a seawater pH and I will tell you what that ratio

    is.
    > : Tell me the pH and
    > : > Alk and I will give the CO2 concentration. Give me the Alk and CO2

    and I
    > : will give you
    > : > the pH. Don't forget the temperature and Salinity.
    > : >
    > : > Alk is defined as;
    > : >
    > : > TA = [HCO3-] + 2[CO3--] + [B(OH)4-] + [OH-] + [Si(OH)3O-] + [MgOH+] +
    > : [HPO4--] +
    > : > 2[PO4---] - [H+]
    > : >
    > : >
    > : > Buffering Capacity is defined as;
    > : >
    > : > BC = dCb/dpH = 2.303 (Kw/ [H3O+] + [H30+] + CKa[H3O+] / (Ka +

    [H3O+])²
    > : >
    > : > In any aqueous solution maximum BC is reached when pH= pKa. Seawaters
    > : maximum BC is at a
    > : > pH of 6 & 9. For all practically purposes seawater has very little
    > : Buffering Capacity, if
    > : > any at all.
    > : >
    > : >
    > : > Alkalinity and Buffer Capacity are closely tied but are NOT the same
    > : thing, it is a
    > : > misunderstanding and use of the term. Do you think water chemistry

    books
    > : would have
    > : > separate sections on Alkalinity and Buffering Capacity if they were

    the
    > : same thing ?
    > : >
    > : > By the way do you know who you are talking to ?
    > : >
    > : > --
    > : > Boomer
    > : >
    > : > Want to talk chemistry ? The Reef Chemistry Forum
    > : > http://www.reefcentral.com/vbulletin/index.php
    > : >
    > : > Want to See More ?
    > : > Please Join Our Growing Membership
    > : > www.coralrealm.com
    > : >
    > : > If You See Me Running You Better Catch-Up
    > : >
    > : >
    > :
    > :
    >
    >
     
    stoutman, Feb 9, 2004
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.