Building DSB in 90 gal tank

[Tyslin]

So,.. to sum all of this up, having a 3" inch DSB is good as long as I have alot of sand sifting critters and burrowers to keep the sand moving or turning over, which makes the Sand more propous and aids disolved oxygen to bacteria. It also helps with the nitrification and denitrification process. Again the sifter and burrowers will take care of this part,...... the worms and crustaceans from the live sand will feed on the plankton, detritus, DOM trapped in the substrate, due to the advection or diffusion process.

Like I stated above having ALOT of sifter and burrowers will help keep the sand propous and that will help the overall nitrification and denitrification process. Anything else besides sifter that can help my sand bed be more propous? would you recommend DSB or 1-2 inches of Arag-Live sand?
Because of all this happening on the DSB I won't have to clean my sand bed correct? Do I have a good understanding Coral Reefer, sorry for this dude It takes me a while to get it down packed. You detailed info on all of the processes is great, just wanted to thank you.

[coral reefer]

Hey, no problem mon'!
I have never cleaned my sand bed...My inverts such as Queen Conch, Nassarius snails, sea Cucumber and worms etc. do the work for me. Occassionally I will quickly run my hand in the sand to stir it a bit but that is it...no vacuuming at all.
Best of luck with your tank and glad I could be of some assistance to ya!!!

[Dyngoe]

Hey Coral,

I don't like to disagree with people online; I do that enough in the "real" world. However, I have to disagree with your statement. Sand sifters do not help in denitrification. In fact, they hinder it. As I stated in my previous post, denitrification requires a lack or complete abscence of O2. In the presence of O2, the proper bacteria will not grow. If you stir up your sand too much, you will be adding extra O2 and thereby halting the denitrification process. I have researched this quite a bit and have come to the conclusion that a good denitrifying bed requires slow water movement where the O2 can be fully removed from the equation. This is similar to what our waste processing plants use, only on a smaller scale.

[inwall75]

First off.....Karma to all of the above for the excellent information.

I love this particular air pump. It runs off of batteries but it plugs in anyway. Whenever it notes the power to the outlet turning off, the battery automatically turns it on. Please note that I recommend removing the airstone. If you go 6 months with the airstone in the water without it ever running, when you need it to blow bubbles, it won't....it will be clogged up. Silent Air B11 Air Pump

While I'm well known here on 3Reef for not being a pro-DSB person, it's not the DSB I'm really against. They've been advertised for years as a miracle cure-all and they really aren't. They come with some Cons as well as some pros and people above have discussed some of them. I've argued about them on many threads but it's not because I don't like them (how can I....I run one on my mantis tank). They just don't work the way that they were described. (Even though I was a business major, I ran the bio-lab to help pay my way through college and even took some micro-biology courses).

Here's one of the Pros that I've been arguing against for years. Just this month, one of the "experts" finally admitted that a DSB is NOT going to melt and buffer your water. (Years ago, I made a smart-alek comment and Jerel asked me if he could put it in his signature. I said, "People think DSB's act like wormholes and the detritus and nutrients are transported to a sister galaxy". It was a hilarious joke between Jerel an myself.....people who were DSB-disciples (the Ronettes) would attack him for his signature and they would praise me for being more level-headed never knowing that I was the one who wrote the quote.

It is apparent from these results that the dissolution of calcium carbonate sand is incapable of providing adequate calcium or carbonate alkalinity by dissolution to aquariums holding even very small amounts of coral and coralline algae. Thus, the implications that such processes are able to sustain reef aquariums with large numbers of scleractinian corals, as suggested by Jaubert (1989), must be called into question. The results here, however, are not surprising and are strongly supported by the literature and the practical experiences of most aquarists.

Applications of Sand in Reef Aquariums: Theory and Practice by Eric Borneman - Reefkeeping.com

[coral reefer]

Originally Posted by Dyngoe

Hey Coral,

I don't like to disagree with people online; I do that enough in the "real" world. However, I have to disagree with your statement. Sand sifters do not help in denitrification. In fact, they hinder it. As I stated in my previous post, denitrification requires a lack or complete abscence of O2. In the presence of O2, the proper bacteria will not grow. If you stir up your sand too much, you will be adding extra O2 and thereby halting the denitrification process. I have researched this quite a bit and have come to the conclusion that a good denitrifying bed requires slow water movement where the O2 can be fully removed from the equation. This is similar to what our waste processing plants use, only on a smaller scale.

you are right, just the nitrification process!!!! The denitrification process is anaerobic. I guess I was rambling on but thank you for correcting me. I don't know everything and make mistakes! Thanks man!

[inwall75]

There's nothing wrong with disagreeing as long as it is done nicely.

DSB's don't work at all like most people think they do. So we can all get into the nitty-gritty if we want.

For instance, here's a common thought. The bubbles in your sand bed are Nitrogen that is liberated by the denitrification process. NOPE....it's pure Oxygen and it's produced by cyanobacteria and it only happens at the edges of your tank where the glass acts like glass fiber and allows your lighting to go deeper into your sandbed. That's why when your critters run around in the sand, you don't have a constant stream of bubble rising from the sandbed.

How much Nitrates really get removed by our DSB's? Actually very little. Ammonification takes over fairly quickly once there is Ammonia in the sandbed (snail poo, worm poo, uneaten food). Then everything completely changes. Instead of Ammonia to Nitrite to Nitrate to Nitrogen gas, you end up with a cycle where the Nitrates turn back into Ammonium then to Nitrite then to....... This can go on for ages because the process of nitrification is just electron transfer.

BTW....the phosphate cycle, Carbon cycle, and Sulphur cycle are also going on 24/7 in a DSB. No one likes to talk about those either.

[Tyslin]

So Dyngoe, your saying that I should not get sifters in my tank? so what should I do about nitrification and denitrification in my tank?

[coral reefer]

I love this guys!!!!!!Good ole' conversation with alot of good input and feedback...this is how we all learn and it sticks in our heads! This is like Monarch notes in high school where you could get answers without having to read the whole book when doing a term paper!!hahaha
Karma to all of ya!
Good questions Tyslin!!!! good feedback Inwall75 and dyngoe!

[inwall75]

Originally Posted by Tyslin

So Dyngoe, your saying that I should not get sifters in my tank? so what should I do about nitrification and denitrification in my tank?

I think that you're misunderstanding him. He's offline right now so let me see if I can help.

Bioturbation (sand-stirring) is NECESSARY for the proper functioning of a sandbed. Diffusion/advection alone cannot bring the nutrients through the sandbed because the biofilms prevent it. You wouldn't think that Van Der Waals forces could have an impact on bacteria but they do.

What you don't want is a monstrous sand-sifting star, a jawfish, a pistol shrimp, etc that move large amounts of sand. Worms, snails, and other small critters are needed.

[Tyslin]

Ok Inwall75,

So I need small sifters for Bioturbation (sand-stirring) which is needed for proper functioning of DSB. Does this create nitrification? or not? what does sand stirring do?

What about denitrification? what do I need to create that process?