Question on adding deep sand bed

[Mando77]

I have decided to add a deep sand bed of about 3 inches in my 29 gallon tank. It is currently around 1 inch. I have had a nitrate problem for a long time and nothing has worked to where I can get keep it close to zero. My only issue is I have an established tank. What is the easiet way to add another 30-40 pounds of sand? Should I take everything out of the tank and transfer it and then add the sand? If so how long should I let the sand sit for before adding my livestock back?

[Jan]

How does a DSB help with nitrates? I thought that they created nitrate problems. Why not add a refugium? I had a 24 gallon nano with nitrate problems and the only thing that helped was when I converted one of the compartments into a refugium. I didn't have anymore nitrate problems after that.

 

I have decided to add a deep sand bed of about 3 inches in my 29 gallon tank. It is currently around 1 inch. I have had a nitrate problem for a long time and nothing has worked to where I can get keep it close to zero. My only issue is I have an established tank. What is the easiet way to add another 30-40 pounds of sand? Should I take everything out of the tank and transfer it and then add the sand? If so how long should I let the sand sit for before adding my livestock back?

[Coral Hind]

Jan,

 

Check this link out from WWM.

 

http://www.wetwebmedia.com/deepsandbeds.htm

 

"One of the principal benefits to deep sand bed methodologies is the potential for natural nitrate reduction (NNR). The speed and extent to which a DSB can reduce nitrate in an aquarium amazes many aquarists

[Coral Hind]

I always just lifted everything up off the existing sand bed and just place the new well rinsed sand in. I never removed any corals and I never had any issues. As long as you have some established live rock you will not have any issues. I would make sure not to disturb the existing sand bed if you can.

 

 

[Glenn]

But is 3" a DSB ?? From most of the articles I've read (I think on RC), you really need to start at 6" and possibly go up from there to get the denitrate benefits of a DSB. If you're truly interested, set up a secondary tank (or sump) with a DSB and add a light and ball of chaeto. My refugium has a shallow sand bed and I seeded it with several live rock rubble pieces to get it started.

[cabrego]

I don't see a real concern with adding LIVE sand to an establish tank, I have added a 20lb bag with no observed effects. It can get dusty if you are not careful-I usually use a tupperware type container with a lid to control the sand, lower the container to the bottom of the tank, and open/slowly pour the sand. This technique has worked well for me interms of minimizing dust.

 

I have a DSB (3-4 inches) in my fuge with cheato and have 0 nitrates for almost a year now...

[Coral Hind]

I currently have no sand anywhere in my system and I have zero nitrates. Clams are a great way to control nitrates in a tank. If you have the lighting you may want to think about adding some.

[trockafella]

I currently have no sand anywhere in my system and I have zero nitrates. Clams are a great way to control nitrates in a tank. If you have the lighting you may want to think about adding some.

 

 

How do clams help..?

[Jan]

They help by absorbing nitrate and ammonia. Some folks use many bivalves in there sump.

 

How do clams help..?

[treesprite]

If you are wanting the DSB for nitrate reduction, you need at the very least 4", and that is only deep enough if you have nothing that digs around in the sand. Why don't you make the DSB separate from the tank?

[zygote2k]

I currently have no sand anywhere in my system and I have zero nitrates. Clams are a great way to control nitrates in a tank. If you have the lighting you may want to think about adding some.

That might work if you have lots of money to get 100 clams to reduce the N03. A DSB in the 'fuge is way easier and less costly to buy/build. I use a DSB that only has about 3" of sand with rock rubble on top.

[Coral Hind]

That might work if you have lots of money to get 100 clams to reduce the N03. A DSB in the 'fuge is way easier and less costly to buy/build. I use a DSB that only has about 3" of sand with rock rubble on top.

 

Your reference to a 100 clams is totally illogical. As normal, obviously you have nothing to base that reference on.

 

Just adding a few nice clams can add color and diversity to a tank while also helping to reduce nitrate. Look at it as an additional benefit to adding these gorgeous creatures to your tank.

[zygote2k]

Yes Mr. Hind, I was being a little sarcastic. I apologize. I'd like to know the methodology to reducing N03 by clams though. I've never heard of that method of nitrate reduction. Doesn't it go against reason to put clams in water that has excess nitrate? Wouldn't they be more likely to die if the nitrate is too high? Obviously you will need a large quantity if the method does work. I think a DSB is easier, cheaper, and less likely to cause grief if the clams die.

[Jan]

Well (scratching my head) I thought clams helped to reduce nitrates and ammonia. It seems as though they may not. I searched for some proof of this and found this great site but according to the author, clams DO NOT help in the reduction of nitrates and ammonia. Quite the contrary, they take beneficial plankton and release ammonia.

 

http://www.chucksadd....com/clams.html

Edited April 1, 2010 by Jan

[Chad]

I think there is a clarification to be made here, tridacnid clams are different from other clams because of their zooxanthellae. If tridacnids do not reduce nitrate and ammonia, why would commercial aquaculture methods add it to growout systems? Most clams are not that different from other organisms we add to our tanks in terms of food goes in ammonia goes out to be dealt with. However, the zooxanthellae processes the inorganic nitrate and ammonia (ammonia preferentially). Yes, the clam produces ammonia, but the zooxanthellae uses some of it. It is a question of out vs. in, tridacnids (with their zooxanthellae) use more nitrate and ammonia than they produce (which is why we so often hear that tridacnids greater than 2" need to be fed... as a side note, the tridacnids are not born with zooxanthellae, they need up ingest it, hence feeding smaller clams). What I am not sure of is how many clams would be necessary to effectively reduce nitrate in a home aquarium. I would venture to guess the number to be more than most of us keep; however, I agree that it is just another benefit to having these beautiful organisms in our system.

 

Here are some sources that state this:

 

http://www.sciencedi...ae03b46a3c3f873

 

http://animal-world....ms/tridacna.htm

 

http://etd.fcla.edu/...12200/alo_m.pdf

[zygote2k]

I think that those articles stated that clams consumed ammonium nitrate as part of their growth and feeding stages specifically for culturing purposes. One article said there were 14000 clams in the raceway, another was a clam farm.

It's hard to make the correlations that adding clams to your system will reduce nitrates. If you have enough clams ( a whole tank full), you might be able to reduce overall levels of nitrate. Generally it is recommended that you have nitrate free water BEFORE adding clams. They are notorious for going south if the water quality is poor.

[zygote2k]

this is from the article that Jan found:

Clams as filtration ? - Having seen this being promoted and asked about, I thought it a good idea to address such a "method". If by chance you read the above anatomy descriptions you would have noted that clams are filter feeders, of plankton. Which can only produce the same waste materials, most notably, ammonia, that any animal that eats would produce. I fail to see how loading an aquarium system with clams could ever have an effect on nitrate production as being suggested by others. Quite the opposite would happen. That and being plankton filter feeders, I would see them as a big competition for food that other tank inhabitants could and would utilize, such as my corals and other invertebrates.

Having a reef system, and trying to provide for the animals food requirments is hard enough without having a number of clams being in direct competition for the same resources. Any area, such as a sump or refugium compartment would much better serve a reef aquarium if used to promote the production of plankton, not its removal.

For nitrate reduction, its not going to happen through the use of clams. For water clarity, sure, if you want to deny your corals the chance at what little plankton our systems can produce. All around, I feel this is just an idea that has not been thought out through to its biological conclussions. As happens quite frequently within this hobby.

[Chad]

I read that link that Jan posted, it is about clams in general (the picture of clam anatomy doesn

[zygote2k]

That statement that they lower DIN might be true, but I believe that we have organic nutrients and not inorganic nutrients in our tanks. What's the difference?

[Chad]

In general, organic nutrients are those that have carbon based molocules (carbohydrates, proteins, sugars etc.) attached to them. Inorganic nutrients are those without carbon based molocules (ammonia, nitrate, nitrite, phosphate, silicate, etc.).

 

 

[treesprite]

Was this thread hijacked or what?

 

When I had a sand bed that was 5", the consensus here was that it wasn't deep enough and I had to dig around for links to articles to support me, most of which said 4 to 6". Supposedly after 6" it's just overkill, though my DSB is 8".

[zygote2k]

My current RDSB is only about 3" and is working well.

[cabrego]

The reality of the situation as I see it is that the right size is the one that works for your set up. There are going to be many factors that muddy the waters so to speak, no one has even mentioned total volume or mass of sand, density of sand, active surface area, etc. I am willing to be a small fortune that at 3-7" deep sand bed (pick your favorite depth) will not work if the active surface area is only 2in^2. If there is anything that I have learned in this hobby it is that there is no "recipe for success", everyone's system is different enough to make this so. You should be willing to experiment a bit with your system, and be patient (as most of us know).

 

If you are battling nitrates, I would recommend a fuge if possible, even a hang on type might be worth it, if you can not plumb an external fuge. Having 0 nitrates makes maintanence so much easier..I don't even do water changes any more!

[Sikryd]

My DSB in my refugium is 6-7" and is made with oolite sand since it is smaller and packs tighter, which allows for less area for oxygen.

[davelin315]

I added a RDSB to my sump and it has done nothing for my nitrates, going on 3 months now I believe since I added it.

 

To be effective, a DSB of any type has to be deep enough to afford space anaerobic respiration to take place. Generally speaking, below 3-4" is considered to be anaerobic. If there are things that stir up the sand, then it can get lower. If your bed is only at 3-4", it's not serving the purpose of a DSB. Think of it as live rock - the anaerobic bacteria is all the way on the inside versus in the top layer of the rock.

 

As far as clams, they do absorb nitrates and ammonia. In fact, younger clams which are even more dependent on food are often fed the equivalent of fertilizer in aquaculture systems to keep up with their high demand. There are other things out there that absorb nitrate and ammonia as well, such as xenia.