Chronic Low Alk

[sen5241b]

I read somewhere on this website that alk is mostly comprised of mag and calcium. If that is so then how can my alk be so low and yet my mag and cal are high? Also, I just started dosing (last night after tests) with Seachem Marine Buffer to bring alk up --is this the solution?

Temp 78
Salinity 1.025
Ph 8.2
Alk 4 dkh
Cal 500
Mag 1800+ (Red Sea, its been this high before)
Phos zero
Nitrates zero

Salt is Oceanic but recently started using Coralife.

 

[yote]

How are your corals doing?
With a DKH of 4,you should be seeing problems with corals,low PH.
What kit are using to test it and how old is the kit?

 

[sen5241b]

I ordered the alk kit from Dr foster 2 or 3 months ago. Coral looks fine. My plate coral is a vibrant green. I think the test is good. I clean the tube carefully, rinse it with tap and then rinse it with tank water before taking sample water. Its been low for the last month or two.

 

[ccCapt]

I read somewhere on this website that alk is mostly comprised of mag and calcium.

Not true at all. Not even possible.

Reef Aquarium Water Parameters
"Like calcium, many corals also use "alkalinity" to form their skeletons, which are composed primarily of calcium carbonate. It is generally believed that corals take up bicarbonate, convert it into carbonate, and then use that carbonate to form calcium carbonate skeletons. That conversion process is shown as:
HCO[SIZE=-1]3[/SIZE]- à CO[SIZE=-1]3[/SIZE]-- + H[SIZE=-1]+[/SIZE]
Bicarbonate à Carbonate + acid
To ensure that corals have an adequate supply of bicarbonate for calcification, aquarists could very well just measure bicarbonate directly. Designing a test kit for bicarbonate, however, is somewhat more complicated than for alkalinity. Consequently, the use of alkalinity as a surrogate measure for bicarbonate is deeply entrenched in the reef aquarium hobby.

So, what is alkalinity? Alkalinity in a marine aquarium is simply a measure of the amount of acid (H+) required to reduce the pH to about 4.5, where all bicarbonate is converted into carbonic acid as follows:
HCO3- + H+ à H[FONT=Arial, Helvetica, sans-serif]2[/FONT]CO3

In normal seawater or marine aquarium water, the bicarbonate greatly dominates all other ions that contribute to alkalinity, so knowing the amount of H[SIZE=-1]+[/SIZE] needed to reduce the pH to 4.5 is akin to knowing how much bicarbonate is present. Aquarists have therefore found it convenient to use alkalinity as a surrogate measure for bicarbonate.
One important caveat to this surrogate measure is that some artificial seawater mixes, such as Seachem salt, contain elevated concentrations of borate. While borate is natural at low levels, and does contribute to pH stability, too much interferes with the normal relationship between bicarbonate and alkalinity, and aquaria using those mixes must take this difference into account when determining the appropriate alkalinity level.
Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in Porites porites.[SIZE=-1]4[/SIZE] In this case, doubling the bicarbonate concentration resulted in a doubling of the calcification rate. Uptake of bicarbonate can apparently become rate limiting in many corals.[SIZE=-1]5[/SIZE] This may be partly due to the fact that both photosynthesis and calcification are competing for bicarbonate, and that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration).
For these reasons, alkalinity maintenance is a critical aspect of coral reef aquarium husbandry. In the absence of supplementation, alkalinity will rapidly drop as corals use up much of what is present in seawater. Most reef aquarists try to maintain alkalinity at levels at or slightly above those of normal seawater, although exactly what levels different aquarists target depend a bit on the goals of their aquaria. Those wanting the most rapid skeletal growth, for example, often push alkalinity to higher levels. I suggest that aquarists maintain alkalinity between about 2.5 and 4 meq/L (7-11 dKH, 125-200 ppm CaCO[SIZE=-1]3[/SIZE] equivalents), although higher levels are acceptable as long as they do not depress the calcium level.
Alkalinity levels above those in natural seawater increase the abiotic (nonbiological) precipitation of calcium carbonate on objects such as heaters and pump impellers. This precipitation not only wastes calcium and alkalinity that aquarists are carefully adding, but it also increases equipment maintenance requirements. When elevated alkalinity is driving this precipitation, it can also depress the calcium level. A raised alkalinity level can therefore create undesirable consequences.
I suggest that aquarists use a balanced calcium and alkalinity additive system of some sort for routine maintenance. The most popular of these balanced methods include limewater (kalkwasser), calcium carbonate/carbon dioxide reactors, and the two-part additive systems.
For rapid alkalinity corrections, aquarists can simply use baking soda or washing soda to good effect."

 

[sen5241b]

All good info. I think I'm on track with using seachem to rasie alkalinity a little.

 

[daugherty]

i use to use seachem reef builder and or reef buffer

 

[sen5241b]

I thank everyone for their help but no one has really understood or solved this problem. Yesterday I started adding Seachem Marine Buffer --about half a teaspoon which is enough to change the alk at least a little. The water turned a little cloudy. I just re-tested everything and now the Ph is 8.3 and the Alk has dropped to 5 dkh !! Thursday, it was 7 dkh. I did add a shrimp and goby last night. (Yes, I re-tested carefully 3x). So, I ask again why is alk dropping? I'm trying to solve this problem before corals start dying.

 

[Bifferwine]

Which test kit are you using? Does it have an expiration date on the box? You may want to buy a different test kit to get a second opinion.

 

[daugherty]

your alk is up 1dkh from what you posted yesterday just keep adjusting every day. if you have a lot of coraline it will deplete alk and cal. as your tak ages it will consume more alk and cal

 

[sen5241b]

your alk is up 1dkh from what you posted yesterday just keep adjusting every day. if you have a lot of coraline it will deplete alk and cal. as your tak ages it will consume more alk and cal

Yes, a misstatement. But it is still way low. The marine buffer was all cloudy when added and the directions said this only happens because of preexisting ionic imbalance? Ionic what?

 

[ndepratt]

Not true at all. Not even possible.

Reef Aquarium Water Parameters
"Like calcium, many corals also use "alkalinity" to form their skeletons, which are composed primarily of calcium carbonate. It is generally believed that corals take up bicarbonate, convert it into carbonate, and then use that carbonate to form calcium carbonate skeletons. That conversion process is shown as:
HCO[SIZE=-1]3[/SIZE]- à CO[SIZE=-1]3[/SIZE]-- + H[SIZE=-1]+[/SIZE]
Bicarbonate à Carbonate + acid
To ensure that corals have an adequate supply of bicarbonate for calcification, aquarists could very well just measure bicarbonate directly. Designing a test kit for bicarbonate, however, is somewhat more complicated than for alkalinity. Consequently, the use of alkalinity as a surrogate measure for bicarbonate is deeply entrenched in the reef aquarium hobby.

So, what is alkalinity? Alkalinity in a marine aquarium is simply a measure of the amount of acid (H+) required to reduce the pH to about 4.5, where all bicarbonate is converted into carbonic acid as follows:
HCO3- + H+ à H[FONT=Arial, Helvetica, sans-serif]2[/FONT]CO3

In normal seawater or marine aquarium water, the bicarbonate greatly dominates all other ions that contribute to alkalinity, so knowing the amount of H[SIZE=-1]+[/SIZE] needed to reduce the pH to 4.5 is akin to knowing how much bicarbonate is present. Aquarists have therefore found it convenient to use alkalinity as a surrogate measure for bicarbonate.
One important caveat to this surrogate measure is that some artificial seawater mixes, such as Seachem salt, contain elevated concentrations of borate. While borate is natural at low levels, and does contribute to pH stability, too much interferes with the normal relationship between bicarbonate and alkalinity, and aquaria using those mixes must take this difference into account when determining the appropriate alkalinity level.
Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in Porites porites.[SIZE=-1]4[/SIZE] In this case, doubling the bicarbonate concentration resulted in a doubling of the calcification rate. Uptake of bicarbonate can apparently become rate limiting in many corals.[SIZE=-1]5[/SIZE] This may be partly due to the fact that both photosynthesis and calcification are competing for bicarbonate, and that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration).
For these reasons, alkalinity maintenance is a critical aspect of coral reef aquarium husbandry. In the absence of supplementation, alkalinity will rapidly drop as corals use up much of what is present in seawater. Most reef aquarists try to maintain alkalinity at levels at or slightly above those of normal seawater, although exactly what levels different aquarists target depend a bit on the goals of their aquaria. Those wanting the most rapid skeletal growth, for example, often push alkalinity to higher levels. I suggest that aquarists maintain alkalinity between about 2.5 and 4 meq/L (7-11 dKH, 125-200 ppm CaCO[SIZE=-1]3[/SIZE] equivalents), although higher levels are acceptable as long as they do not depress the calcium level.
Alkalinity levels above those in natural seawater increase the abiotic (nonbiological) precipitation of calcium carbonate on objects such as heaters and pump impellers. This precipitation not only wastes calcium and alkalinity that aquarists are carefully adding, but it also increases equipment maintenance requirements. When elevated alkalinity is driving this precipitation, it can also depress the calcium level. A raised alkalinity level can therefore create undesirable consequences.
I suggest that aquarists use a balanced calcium and alkalinity additive system of some sort for routine maintenance. The most popular of these balanced methods include limewater (kalkwasser), calcium carbonate/carbon dioxide reactors, and the two-part additive systems.
For rapid alkalinity corrections, aquarists can simply use baking soda or washing soda to good effect."

I'm definitely in love with you cccapt.

 

[ndepratt]

quick fix to low alk would be to bake baking soda (sodium bicarbonate) in the oven for 3 hours at 350 degrees.

then you have a TON of sodium bicarbonate to raise alk without affecting your PH. ;)

 

[ccCapt]

I thank everyone for their help but no one has really understood or solved this problem. Yesterday I started adding Seachem Marine Buffer --about half a teaspoon which is enough to change the alk at least a little. The water turned a little cloudy. I just re-tested everything and now the Ph is 8.3 and the Alk has dropped to 5 dkh !! Thursday, it was 7 dkh. I did add a shrimp and goby last night. (Yes, I re-tested carefully 3x). So, I ask again why is alk dropping? I'm trying to solve this problem before corals start dying.

Stop dosing everything. Just do a 10% water change every 2-3 days and don't bother testig anything. Keep doing water changes with no dosing for at least 2 weeks then test your parameters. They should match the parameters of the salt you use.

Before you started dosing, did you test everyday (without dosing anything) to determine that amount of alk/ca comsumed by your tanks inhabitants daily? How did you come up with your dosing schedule?

quick fix to low alk would be to bake baking soda (sodium bicarbonate) in the oven for 3 hours at 350 degrees.

then you have a TON of sodium bicarbonate to raise alk without affecting your PH. ;)

Save some energy. You only need to bake it for 1 hr at 350. ;)

 

[JAG107]

Oceanic salt will give you lower alk levels than, say, reef crystals or other popular brands. Oceanic has loads of mag and calc though. cccapt has sent you in the right direction.

 

[yote]

quick fix to low alk would be to bake baking soda (sodium bicarbonate) in the oven for 3 hours at 350 degrees.

then you have a TON of sodium bicarbonate to raise alk without affecting your PH. ;)

Actually,baked baking soda will raise the PH pretty high if you dose it all at once.
When I dose the baking soda,I mix it in a cup of RO water,then spread the dose out over a couple of hours.That way it dont shoot the PH sky high.

 

[daugherty]

unbaked baking soda will lower the alk from what i have read.

 

[ccCapt]

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System

"Recipe #1 (baked baking soda) is for use in reef aquaria whose pH is normal to low. In practice, more reef aquarists end up choosing this recipe than Recipe #2. It will tend to raise pH due to its alkalinity part's elevated pH, as do most of the commercial two-part additives. The increase in pH depends on the aquarium's alkalinity and, of course, on how much is added. Adding on the order of 0.5 meq/L of alkalinity increases the pH by about 0.3 pH units immediately upon its addition (and even higher, locally, before it has a chance to mix throughout the aquarium)."

"Recipe #2 (raw baking soda) is for use in reef aquaria whose pH is on the high side (above 8.3 or so). It will have a very small pH lowering effect when initially added. The pH drop achieved will depend on the aquarium's alkalinity and, of course, on how much is added. Adding on the order of 0.5 meq/L of alkalinity drops the pH by about 0.04 pH units immediately upon its addition."

 

[sen5241b]

The alk is back at 4 even though I have been dosing with Seachem Marine Buffer! Ph is still around 8.2. The nice thing about Seachem Marine Buffer is that it cannot raise Ph above 8.3 even if you overdose. I'm thinking a 40% water change. I've done 40% changes in the past many times and nothing was for the worse.

Good advice capt. I hadn't thought about measuring actual daily usage.

 

[ccCapt]

The nice thing about Seachem Marine Buffer is that it cannot raise Ph above 8.3 even if you overdose.

Well, that's not exactly true. The reason the pH is "supposed" to stop at 8.3 is because of all the boron added to the buffer...and that's not exactly a good thing.

Boron in a Reef Tank (and its effect on pH buffering)

Some brands of alkalinity supplements or “buffers” are claimed to contain added boron (such as Marine Aquarium Buffer, Pro●Buffer dKH, and Superbuffer dKH made by Kent), while others do not (such as Reef Builder, Reef Buffer, and Reef Carbonate made by Seachem). Unfortunately, those that contain boron do not indicate how much, either on the bottle, or when the manufacturer is directly asked. The only statement made is that it is an “important contribution.” Consequently, it is not apparent, without lab testing, whether the amounts of boron present are large enough to be useful. It is also not apparent whether the amounts present might be high enough to invoke some of the undesirable effects of boron that are described below.​

One additional complication that comes from substantially elevated borate is the confounding of the interpretation of alkalinity tests. When reef aquarists are concerned about alkalinity, they are almost invariably concerned with the alkalinity that comes from bicarbonate and carbonate, and it is largely used as a surrogate measure of bicarbonate, which is necessary for calcification. Nearly all hobby test kits measure alkalinity with a single titration that provides total alkalinity, which is the sum of bicarbonate, carbonate, and borate alkalinity. When the levels of boron are similar to natural levels, then the contribution of borate to that test is minimal, and is generally safely ignored in guidelines for alkalinity (for example, keeping a reef tank at 2.5-4 meq/L total alkalinity). However, if the boron level is substantially above natural levels, as it is in the Seachem salt mix with 12x normal levels, borate can actually begin to dominate such tests, and makes knowing the real bicarbonate and carbonate alkalinity much more difficult. Seachem sells a special borate alkalinity test kit to try to disentangle these effects, but that is only really necessary with tank water that contains greatly elevated boron levels.

 

[sen5241b]

Couple weeks back I tried a series of smaller 15-20% water changes and it raised the alk only 1 point. So yesterday I did a 40+% change using a new salt -coralife- and the crappy salt has all this white, powdery crud in the bottom of the change out bucket. I let most of it settle and used the water anyway but the tank got all clouded up. The water slowly cleared. If you ever done the math, four 10% changes is not equal to one 40% change out.

Oceanic, I've been told, has low alk. The coralife plastic bags don't reseal easily and it has the white crud. What salt best maintains alk!? Later today, I'll re-check the alk.