Melonbob
Reef enthusiast
Can you just add sand as you go along? Right now I only have about 1" of sand in my 46g and I heard alot more would be better. Can I just add sand? How would the best way of doing this be?
deep snad bed?
- Thread starter Melonbob
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RyanG
Reef enthusiast
If it were dead sand I would think you could add some but the fine sand needed for DSBs would probably cloud the tank for at least days if not weeks and would mess up your pumps. The funnel/pvc method would be your best optionIMO but would be very tedious and time consuming.
Rcpilot
Reef enthusiast
Use a funnel and pour the sand into a container with a tight fitting lid.
Pour dry sand into the container (2 liter bottle?) and then fill it with water. Cap it up tight and shake. Dump the cloudy water down the drain. Repeat until it's mostly clear.
Then I bet you could dump that sand out of the bottle if you hold the bottle down low near the bottom of the tank. It shouldn't make too much dust if you rinse it first. It's gonna get cloudy, but not near as bad if you rinse it first. Just like rinsing carbon before you add it.
As far as your bacterial colonies on the existing sand:
You'll be burying the old sand and thereby suffocating the existing bacteria in the sand bed. They need oxygen and they won't get any at the bottom of a 4" DSB.
BUT, I think you could add sand over time and get it deep enough to not make a difference. Add one inch of sand at a time. Or fill up one corner with 6" of sand and let it slowly settle it's way out into the tank. Wait 3 or 4 weeks for it to settle in and grow bacteria. Then dump 10 or 20 pounds in a different corner after you rinse it and waited 3 weeks.
4 or 5 times and you'd be set. You'll see a mini cycle each time, but it shouldn't be bad unless you cover the entire sand bed at once. You still need some of the bacteria on the surface to handle the mini cycle of burying some of them, so just cover about 25%-- 30% of the sand bed at once. In 2 or 3 months time, you'll have a 4" DSB thats fully established and functional at removing nitrates.
But, thats just how I'd do it. I've learned to go very slow. This is a long term hobby and 2 months to put a DSB into the bottom of an existing tank is nothing to me. Some people would probably just dump 100lbs of sand in the tank and not even worry about it for a second. Either way would probably work.
Pour dry sand into the container (2 liter bottle?) and then fill it with water. Cap it up tight and shake. Dump the cloudy water down the drain. Repeat until it's mostly clear.
Then I bet you could dump that sand out of the bottle if you hold the bottle down low near the bottom of the tank. It shouldn't make too much dust if you rinse it first. It's gonna get cloudy, but not near as bad if you rinse it first. Just like rinsing carbon before you add it.
As far as your bacterial colonies on the existing sand:
You'll be burying the old sand and thereby suffocating the existing bacteria in the sand bed. They need oxygen and they won't get any at the bottom of a 4" DSB.
BUT, I think you could add sand over time and get it deep enough to not make a difference. Add one inch of sand at a time. Or fill up one corner with 6" of sand and let it slowly settle it's way out into the tank. Wait 3 or 4 weeks for it to settle in and grow bacteria. Then dump 10 or 20 pounds in a different corner after you rinse it and waited 3 weeks.
4 or 5 times and you'd be set. You'll see a mini cycle each time, but it shouldn't be bad unless you cover the entire sand bed at once. You still need some of the bacteria on the surface to handle the mini cycle of burying some of them, so just cover about 25%-- 30% of the sand bed at once. In 2 or 3 months time, you'll have a 4" DSB thats fully established and functional at removing nitrates.
But, thats just how I'd do it. I've learned to go very slow. This is a long term hobby and 2 months to put a DSB into the bottom of an existing tank is nothing to me. Some people would probably just dump 100lbs of sand in the tank and not even worry about it for a second. Either way would probably work.
sen5241b
Reef enthusiast
a 'snad' bed? The new thing?
Seriously, user Kevin Simmons added sand not too long ago and it introduced a disease 'marine velvet' that wiped out all his fish. You might want to avoid the type he used.
Seriously, user Kevin Simmons added sand not too long ago and it introduced a disease 'marine velvet' that wiped out all his fish. You might want to avoid the type he used.
I just move the top of the existing sand to one side put down the new sand and then spread the old sand back over the top of the new sand. To rinse the sand before use I just cut the top out off the bag stick a water hose all the way down to the bottom of the sand and let the water run for a while. I then turn off my circulation system in the tank, place the whole sand bag into the bottom of the tank and slowly tip it to pour out the sand. I typically have to wait only 20 to 30 minute to turn the circulation back on. Aragonite sand only has a half life of about 8 to 12 months, so am putting a new bag of sand in my tank at least once every month to two months at most. It looks like it settles, but it actually dissolves. I use Coral Sea aragonite at sizes of 0.1 to 1.0 mm. 400 lbs in a 120 gallon tank then toop it with 20 pound of GARF grunge.
UnderwaterWorld
Reef enthusiast
would another inch or two or sand in a tank make a big difference in cutting down on the algae and what not?
Bifferwine
I am a girl
Another inch or two would not make a difference if you only have 1 inch already. A DSB should be at least 4 inches deep to be effective, and even that is really shallow.
If you want to add more sand, it's not a problem to do so using any of the methods mentioned above, and every tank needs to replace dissolved sand periodically anyways, but have a 2 or 3 inch bed instead of 1 inch won't make a difference in your nitrate levels.
If you want to add more sand, it's not a problem to do so using any of the methods mentioned above, and every tank needs to replace dissolved sand periodically anyways, but have a 2 or 3 inch bed instead of 1 inch won't make a difference in your nitrate levels.
Biffers right. The standard aragonite rule of sand beds (1.0 mm or smaller in diameter) is more than four inches and less than one inch. That depth recommendation increases with larger sand sizes. In between those depths you are basically just creating a nutrient trapping store house. A depth of four inches of fine sugar sand gives you a chance at denitrification bacteria populations in numbers large enough to at least help control nitrates, a depth at 6 inches or more can actually eliminate normal accumalations of nitrates. The half life of aragonite sand in a deep sand bed and is only 12 to 18 months or less so constant replenishment is required. However, the calcium, strontium, cabonates and magnesium that make up the sand does enter the water mix so it is not lost, it is used by corals and coralline algae for growth.
ccCapt
Reef Hacker
WOW I thought I had a decent grasp of reef chemistry, but this is something else. Can someone be so kind and explain, in simple terms, what all this means?
Aragonite sand only has a half life of about 8 to 12 months. - What does this mean? What are the circumstances for this to take place. Please provide a reference...if possible.
so am putting a new bag of sand in my tank at least once every month to two months at most. It looks like it settles, but it actually dissolves - How does it dissolve? I understand the pH must be low, around 7, before aragonite starts to dissolve. So then this means the pH at the bottom of a deep sand bed has a pH of 7? Isn't this the basics of how a calcium reactor works? Inject co2 to lower the pH, which then dissolves the media (such as CaribSea A.R.M. - aragonite reactor media). Is your tank just a big calcium reactor?
I just move the top of the existing sand to one side put down the new sand and then spread the old sand back over the top of the new sand. - So there is no problem disturbing the dsb and no risk of releasing any contaminants? I never used a dsb, but it was my understanding they should not be disturbed. There is no problem releasing water that has a pH of 7, if that's how the sand dissolved in the 1st place?
the calcium, strontium, cabonates and magnesium that make up the sand does enter the water mix so it is not lost, it is used by corals and coralline algae for growth. - If you "use" up a 40lb bag, and that 40 lbs dissolves, once again where does it all go? You mean to say you get 20 lbs (that's 1/2 of what was dissolved...dunno where the other half might go) worth of coralline and new hard coral growth every month? Damn, your tank would be a solid chunk of calcium carbonate after a few years.
I'm not looking for any arguements, just some logical and sensible answers to these few questions.
Aragonite sand only has a half life of about 8 to 12 months. - What does this mean? What are the circumstances for this to take place. Please provide a reference...if possible.
so am putting a new bag of sand in my tank at least once every month to two months at most. It looks like it settles, but it actually dissolves - How does it dissolve? I understand the pH must be low, around 7, before aragonite starts to dissolve. So then this means the pH at the bottom of a deep sand bed has a pH of 7? Isn't this the basics of how a calcium reactor works? Inject co2 to lower the pH, which then dissolves the media (such as CaribSea A.R.M. - aragonite reactor media). Is your tank just a big calcium reactor?
I just move the top of the existing sand to one side put down the new sand and then spread the old sand back over the top of the new sand. - So there is no problem disturbing the dsb and no risk of releasing any contaminants? I never used a dsb, but it was my understanding they should not be disturbed. There is no problem releasing water that has a pH of 7, if that's how the sand dissolved in the 1st place?
the calcium, strontium, cabonates and magnesium that make up the sand does enter the water mix so it is not lost, it is used by corals and coralline algae for growth. - If you "use" up a 40lb bag, and that 40 lbs dissolves, once again where does it all go? You mean to say you get 20 lbs (that's 1/2 of what was dissolved...dunno where the other half might go) worth of coralline and new hard coral growth every month? Damn, your tank would be a solid chunk of calcium carbonate after a few years.
I'm not looking for any arguements, just some logical and sensible answers to these few questions.
**Just as it says, half of the aragonite will be gone within 8 to 12 months. Half life is a term most often used to describe the nuclear isotopes radioactivity decline with age (it is a little more complicated than that, but that is close enough). Check any other reef site (wet web media or RC) under deep sand beds if this site does not supply that data in its articles section, or ask Fenner or Calfo at the Wet Web Media site. It is common knowledge. Or should be anyway. If not just PM John, our Super, Super Moderator.
**Aragonite starts dissolving around 8.2, however that is the extreme low end. 8.0 and lower is where it realy starts disappearing. In reference crushed coral does not dissolve until a pH of 7.6 or lower. Yes, the normal buffering proceesses in a marine tank is much a kin to a calc reactor.
**This is in general, if you have a shallow bed and want to deepen the bed. For a deep bed you just add continous thin layers on top of the existingbed. No more tha a maximum 1/2 inch at a time should be added atop the existing deep bed.
**You will be surprised how little calcium is in a solid substance. there is a lot of air in calcite products as the have a low density and are quite porous. The silica that comes with all sand, even aragonite (beach san is typically silica) will be left behind. Water changes dilute what is not needed and taken up by themarine organismsin a tank. I have never heard anyone using a deep sand bed say the dissolving sand contributed to much acalcoum, carbonate, magmnesium or thorium to their systems. It si recommende with deep sand beds that the pH be kept at the 8.3 to 8.6 range where excess dissolving of aragonite can cause clumping problems, but this is genearally just a problem with commercialgrowers who do not keep living critters in ther sand beds taht stir the sands and prevent clumping.
I'm not looking for any arguements, just some logical and sensible answers to these few questions.
**Aragonite starts dissolving around 8.2, however that is the extreme low end. 8.0 and lower is where it realy starts disappearing. In reference crushed coral does not dissolve until a pH of 7.6 or lower. Yes, the normal buffering proceesses in a marine tank is much a kin to a calc reactor.
**This is in general, if you have a shallow bed and want to deepen the bed. For a deep bed you just add continous thin layers on top of the existingbed. No more tha a maximum 1/2 inch at a time should be added atop the existing deep bed.
**You will be surprised how little calcium is in a solid substance. there is a lot of air in calcite products as the have a low density and are quite porous. The silica that comes with all sand, even aragonite (beach san is typically silica) will be left behind. Water changes dilute what is not needed and taken up by themarine organismsin a tank. I have never heard anyone using a deep sand bed say the dissolving sand contributed to much acalcoum, carbonate, magmnesium or thorium to their systems. It si recommende with deep sand beds that the pH be kept at the 8.3 to 8.6 range where excess dissolving of aragonite can cause clumping problems, but this is genearally just a problem with commercialgrowers who do not keep living critters in ther sand beds taht stir the sands and prevent clumping.
I'm not looking for any arguements, just some logical and sensible answers to these few questions.
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ccCapt
Reef Hacker
Thanks for taking the time to reply, even tho I don't really see any answers. Let's say we can agree on disagreeing.
I'm glad you mentioned ReefCentral. PM me if you want to know what some of the chemistry experts over there said about your half life theory.
I would still love to know what happens to the dissolved 40lbs, let's make it 20 lbs/month of sand you add to your tank. I wonder if there is any other person on this forum who has to add 20 lbs of sand to their tank each month...or each year.
But anyway, thanks again for the reply.
I'm glad you mentioned ReefCentral. PM me if you want to know what some of the chemistry experts over there said about your half life theory.
I would still love to know what happens to the dissolved 40lbs, let's make it 20 lbs/month of sand you add to your tank. I wonder if there is any other person on this forum who has to add 20 lbs of sand to their tank each month...or each year.
But anyway, thanks again for the reply.
Rcpilot
Reef enthusiast
Where does the dissolved sand go? Read Fatmans first post again. It gets used by corals. How do you think LPS corals make those hard skeletons? What about SPS corals? Yes, they use the calcium in the water, but your DSB is also going to dissolve and release calcium into the water too.
I don't know the chemistry behind it like Fatman, but I have firsthand experience with a dissolving DSB. Mine started out about 6" deep and it's down to 5" in about 9-10 months. I'll probably add some this summer or around the 1-year mark.
I don't know the chemistry behind it like Fatman, but I have firsthand experience with a dissolving DSB. Mine started out about 6" deep and it's down to 5" in about 9-10 months. I'll probably add some this summer or around the 1-year mark.
Alexander
Reef enthusiast
this is an interesting topic I never knew about.
and if I read right the sand will do this in a normal sand bed too?
and if I read right the sand will do this in a normal sand bed too?
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ccCapt
Reef Hacker
Please...re-read what he said.
1st it was - the calcium, strontium, cabonates and magnesium that make up the sand does enter the water mix so it is not lost, it is used by corals and coralline algae for growth.
and then - I have never heard anyone using a deep sand bed say the dissolving sand contributed to much acalcoum, carbonate, magmnesium or thorium to their systems.
So which is it? 40 lbs (which gets added) get used by calcification and you have 40 lbs of hard coral skeleton and coralline or 40 lbs dissolves but doesn't contribute to the system? Where does it go?
For the sake if this discussion, say aragonite does dissolve at a pH of 8. And let say 20 lbs dissolves per month. Also, I think it's safe to say calcium reactor media is aragonite (CaribSea calls their reactor media A.R.M. - aragonite reactor media). If 20 lbs dissolves at 8 pH, how much will dissolve at the much, much lower pH inside a ca reactor? I don't know of anyone or ever heard of anyone using 20 lbs of reactor media per month, and using the logic of aragonite dissolving at 8, it should be way more than 20 lbs.
So again...where does all this dissolved material go?
Rcpilot
Reef enthusiast
Corals
sen5241b
Reef enthusiast
I don't think rcpilot is doubting the process. I think its an issue of quantity. Pound for pound it doesn't seem like even a tank chock full of corals could absorb that quantity of dissolved aragonite. Perhaps, some of the dissolved aragonite comes out during water changes.
reeffreak
Reef pro
I'm one of those people who loses about 1'' of sand a year on generally shallow 2'' bed.I do have to agree with Fatman that even at a pH of 8 and higher,aragonite does dissolve.I've seen it dissolve even faster the 5 years or so I ran a plenum/dsb.I would lose 2-3'' or more per year if it wasn't my invention adding 1/2'' more sand every few months to make up for the dissolved sand.Purely,anectotal but I've notice it dissolved faster after the 2nd year when the dsb really matured.My guess,the lack of oxygen,lack of photosynthesis in the deepest part of the sand bed contributed to rapid aragonite dissolving.It's not far fetch to say the void,lack of oxygen had that area pH much lower than the rest of the system.I did notice that my mix reef had extremely fast coralline growth,never needed to be dose with calcium nor buffer ever.The LPS corals and coralline grew at a rate I never been able to replicate when I moved to a shallow bed.
Alexander
Reef enthusiast
so reeffreak, if you had such good results in growth with a dsb, why are you not running one now? are there drawbacks that made you decide not to (other than the actual look of a massive sandbed)
ccCapt
Reef Hacker
This may be of some interest.
Chemistry and the Aquarium: Calcium By Randy Holmes-Farley
....Consequently, aragonite first becomes soluble in seawater when the pH drops below about 7.7 (this value might be more like 7.5-7.7 in reef tanks where the alkalinity is often higher than in seawater). That level is attained in some sand beds, and permits the dissolution of some of the sand.
The rate of dissolution is fairly low, however, because the rate of delivery and degradation of organics (or certain nitrogen compounds) deep enough in the sand to permit a pH drop is fairly low. The rate will, however, vary from tank to tank as the different ways of delivering organics to deeper parts of the sand will vary (diffusion; movement by organisms; death of organisms, etc). Note that the need to oxidize the organics in deeper parts of the sand to permit dissolution of the sand has nothing to do with the oxygenation of the sand. It has more to do with the fact that at near surface regions of the sand, the pH will be closer to that of the tank water by acid and base transfer from the water column, and you need to be deep enough to permit a lower pH to become established.
Chemistry and the Aquarium: Calcium By Randy Holmes-Farley
....Consequently, aragonite first becomes soluble in seawater when the pH drops below about 7.7 (this value might be more like 7.5-7.7 in reef tanks where the alkalinity is often higher than in seawater). That level is attained in some sand beds, and permits the dissolution of some of the sand.
The rate of dissolution is fairly low, however, because the rate of delivery and degradation of organics (or certain nitrogen compounds) deep enough in the sand to permit a pH drop is fairly low. The rate will, however, vary from tank to tank as the different ways of delivering organics to deeper parts of the sand will vary (diffusion; movement by organisms; death of organisms, etc). Note that the need to oxidize the organics in deeper parts of the sand to permit dissolution of the sand has nothing to do with the oxygenation of the sand. It has more to do with the fact that at near surface regions of the sand, the pH will be closer to that of the tank water by acid and base transfer from the water column, and you need to be deep enough to permit a lower pH to become established.
reeffreak
Reef pro
Red,
At that time rapid growth(coralline and corals)was great.....until I had to scrape coralline off powerheads and side/front glass.Everybody loves things to grow fast until they achieve it.Fast growth is overrated to me,I prefer them to grow slow and not take all the space away from future corals.I wish I still had pics of this massive frogspawn which could of possibly had 50,maybe 60 or 70 heads taking up a quarter of a 72g. tank.So for me,I hate fragging,hate scraping coralline and pumps and hate the look of all that sand especially the black crude below the sand level....all that done it in for me.One other thing,I did dsb for denitrication not the other things.
I still have a dsb in a way but no way large enough to replicate similar results as in my old 72g.Having 25g./6'' bed refugium in a 210g. isn't quite enough and that's a good thing for me.
At that time rapid growth(coralline and corals)was great.....until I had to scrape coralline off powerheads and side/front glass.Everybody loves things to grow fast until they achieve it.Fast growth is overrated to me,I prefer them to grow slow and not take all the space away from future corals.I wish I still had pics of this massive frogspawn which could of possibly had 50,maybe 60 or 70 heads taking up a quarter of a 72g. tank.So for me,I hate fragging,hate scraping coralline and pumps and hate the look of all that sand especially the black crude below the sand level....all that done it in for me.One other thing,I did dsb for denitrication not the other things.
I still have a dsb in a way but no way large enough to replicate similar results as in my old 72g.Having 25g./6'' bed refugium in a 210g. isn't quite enough and that's a good thing for me.
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