Building DSB in 90 gal tank

Hello fellow Aquarists,

Just want to say that I am new to this hobby and that the folks in the 3reef forum have been awesome. All of you guys and gals have great info about reef keeping. It has been a pleasure interacting with you because you folks are very honest about all aspects of reef keeping. Just being here with you talking about different aquarium setups, info on equip and troubleshooting problems has been fun.

So on to my question, I have a 90 Gal all glass tank with corner overflow, I want to setup a 3 inch DSB. I believe for a 90 Gal I would need about 130lbs of sand to get 3 inches, can anyone confirm that? thanks. Anyway I am going to buy 90 lbs of Arag-Alive (special grade sand 1-2 mm) and seed it with Live Sand that is teeming with Beneficial worms and crustaceans. I read somewhere that if you have a 3" DSB in the main tank with live worms and crustaceans that it would eliminate detrius from building up on your sand and denitrify the water creating an oxygen rich environment as well as remove nitrate from the tank. If I explained that incorrectly please correct me.

Anywho, is there anything wrong with I am attempting to do with my DSB? Is there something that I shouldn't be doing? is there something that I should be doing? is this plan a good one? please your opinion and help is apprecitated, thanks again people. ;D

 

Hi, if i didnt say so before welcome to 3reef! IMO 3" isn't really a DSB. I would go for 4"+ if you really want the benefits of a DSB. If not dont waste your money on extra sand, get enough that its pleasing to your eye and thats it.

just my 2 cents.

Marc.

 

Hi,

First off, I'll say that DSB setups are under review right now in the aquarium society. There are potential benfits as well as potential down-falls. My prefernece is ~1.5"-2", or just enough to have ~1" over the tank trim. That said, let's adress your particular question:
Live sand in itself will not provide enough sifting action to keep clean and remove detrius. Since you are using a fine gain sand, you can of course use sand sifting stars or use nasarius snails or my FAVORITE a horseshoe crab. My crab is like my night time gardner. In the morning I have clean tracks where he it looks like he "mowed" my sand. Either way you will NEED additional sifting to keep the sand clean.
Put a DSB in your refugium, that's my $.02.

 

+ that. DSB min is 4-5 inches. Let us know what you do.

 

Well guys thanks for your input. Maybe if I tell you what I want to do and explain why,... you can tell me where I might be going wrong or what I can be better. The following is what my setup will have.

90 gal Tank/w corner overflow
megaflow sump
supreme magdrive pump(return)
90 lbs of Live Fiji Rock
130 lbs of Live sand
Outer Orbit 2-150 MH 10,000K, 2-130 Compact Fluorescent
Turboflotor 1000 Multi

Ok, first off I bought the sump so that most of the equip will be installed there instead of the main tank. The sump came with bio-balls that will help build aerobic bacteria and that will help eliminate nitrite and at the same time
build nitrate. The problem with Bio-balls from what I have read is that it will at times increase nitrate levels in your main tank, which is not good. Ok I understand that, so I thought that by creating a DSB with live critters like crustaceans and worms in the main tank, that the nitrate levels will be eliminated by the denitrifying process of the DSB, which in turn helps the enironment in the tank. Also by having live Rock it will help it that much more.
If anything in my theory if off or if it sounds that I lack more info on a certain topic, please correct me.

 

Hi Tyslin,
A deep sand bed is good for a few reasons such as bacteria can adhere to it, thus increases nitrification and denitrification. Sand bed provides an important biotope for which worms, small crustaceans and inverts can live, and it offers food stuff to fish such as Sleeper and Shrimp Gobies as well as Dragonets.
However, a deep sand bed doesn't come without its downfalls. If you have a power failure, your tank will be depleted a lot sooner than someone who doesn't have a DSB. The reason for this is because, all the living bacteria and living organisms in your benthic area(substrate) consume DO(dissolved Oxygen) and give off CO2 so the more sand you have, the more bacteria you have thus the qiucker the oxygen becomes depleted.
As for the DSB not allowing detritus to accumulate, that sttement isn't totally correct. It will keep detritus out for a longer period of time if you have small grain as oppossed to crushed coral or more coarse sand but eventually through diffusion or advection the detritus will accumulate and end up being drawn into your deep sand bed. Detritus as well as plankton, DOM, and POM will be basically sucked into your gravel/substrate and accumulate there.
By having sand sifters, and deposit feeders/filter feeders such as Holothuroid Sea Cucumbers, they will feed on the matter that gets trapped in your substrate through this process of advection or diffusion which is very simialr> defined basically by the speed of the water movement in the benthic area of your tank.
By having these sand sifters and burrowing organisms, you are able to keep your substrate porous which enable increased water flow and oxygen into your sand bed.
The other thing to point out is that advection causes a gradual adsorption of detritus etc. as I mentioned above. This process will reduce the amount of biological nitrification and denitrification that takes place in your sand bed. This is another reason to have sand sifters and burrowing organisms in your substrate.
Oh yeah, one other important thing to mention...the Arag-alive doesn't contain any crustaceans or worms, just the basic bacteria!!!!! I don't know if you know that or not...maybe I just didn't understant your input about live sand teeming with crustaceans and worms. If you could get some mature sand from an existing tank at a local pet shop for instance you will be able
aquire a vary diverse amount of beneficial organisms not found in those pre packaged "live sand" which IMO is a waste of your money!
Best of luck with your tank.

 

Hey Ty,

OK, let me at $.02 to my already $.02:
Get rid of the bio-balls. No one I know that has a successful reef is running them. You may not start out with coral, but you WILL end up there. It's as sure as the sun rising. So, your best bet is a refugium.
Also, a true DSB needs little "stirring" to denitrify. I could find and site articles on the process, but denitrification is anaerobic. So, you need the sand to be relatively stagnant so all of the O2 is burned up. This is where the problem resides, maintaining a DSB is hard because it takes much longer to balance and has the possibilty of spiking later on.
So, go with a fuge. The macro algae in there eats NO3 and CO2 to create O2 and biomass. The plants use NO3 as the protein for their growth. It amkes for a great system. The main tank builds all the necessary food for the macro algae and the fuge in turn makes O2 for the tank and, if lucky, copeopods for your fish and inverts. I can't stress the benefits of the fuge enough. Mine made a WORLD of difference in my tank.

 

Hi Coral Reefer,

So if my power goes out,... the faster my oxygen levels in my tank will be depleted because of the live stuff in my sand bed? wouldn't a air pump be helpful in that situation until power is restored? Also thanks for the info about the detrius on my sand bed I guess I'll have to buy sand sifters and filter feeders for my tank. So by having these sifters in the sand bed they will feed on the matter that creates detrius on the sand bed, sorry just want to get good understanding for what you are saying, it's not you it's me.

Another reason for having sifters and filter feeders is that the amount of biological nitrification and denitrification that takes place in your sand bed will NOT be decreased,correct? So if I do a DSB,.. the things that I need to have are Sand Sifters, filter feeders, and Air pump. Is that right?

By the way the Live Sand I was referring about was from Foster's and Smith. On one page they have Arag-Live sand and on another page where the live rock is they have something called Live-sand with worms e.t.c. The Arag-live sand didn't say that it has worms and stuff, only bacteria like you stated, but the live-sand did say it had worms and stuff. Didn't have a name brand, but was really expensive. Any info is appreciated.

 

Thank Dyngoe, I think that's where I am going to be heading,... after all of the input I getting on DSB. Thanks again dude.

 

You want to have sand sifters and burrowers, to make your sand bed more porpous which aids DO to the bacteria etc. and helps with the nitrification and denitrification process.
exactly!!!! If your power goes out, the best thing you can do is to have a battery powered pump and an air stone to add beneficial oxygen.
The worms and such will feed on the plankton, detritus, DOM trapped in the substrate, due to the advection or diffusion. Keeping the substrate as porous as possible is the key.
Biofilm can also play a role in sand clumping though not the same as precipitation of calcium carbonate causing a hardening of the aragonite sand. Biofilm is a bacterial film by the way!