My deep sand bed

[Lyotim88]

So at first i was told and have always read that a deep sand bed has to be a minimum of 4". Now i was just told by somebody else that 4" isn't enough and it has to be a minimum of 8-10" So which is it? I only have a 55 gallon and can't fit 8 or 10" of sand.

[nickbme06]

Stick with 4" on a 55gal. It really just depends on what your goign to be having in the tank, but generally a 4" sandbed is ok. You can even go less if you have a nice sized fuge and make a good 6" bed in there.

[thegrun]

4" to 6" is fine. There is some research out there now that seems to indicate that the real benefit from a DSB is the intermittent zone between oxygenated and anaerobic. So it is questionable if there is any benefit to going deeper than 6", 4" will be fine.

[Aquarist007]

I would keep the sand bed to 2 inches in the display tank
Later on if you want to add a refugium you can run a deepsand bed of 6 inches in there

[nickbme06]

Also keep in mind that if its a normal tank with the plastic aroudn bottom and top, be sure to measure from the bottom glass and not just what you see above the plastic when you fill it up

[WaterKeeper]

Four inches is the magic number. Less, and you don't get enough oxygen depletion in the bed while very deep beds tend to go completely anaerobic at the bed's bottom and that can lead to sulfate reduction, which creates hydrogen sulfide in the bed.

[nickbme06]

that and hold nitrates.. So dont go over 4", expec just starting off, unless your doing it for something particular and you knwo what your doing. Any less and you will have a hard time keeping your levels at 0

[WaterKeeper]

Well we are not dealing in millimeters here. A slightly more shallow bed will probably work and plenum tanks use beds as deep as 8" without any problems.

[Lyotim88]

thanks for the replies guys. Now that sounds exactly like what the marine biologist at my LFS said. So there is a benefit to 4" right? Then i wonder why i was just told 8-10" minimum?

[nickbme06]

They may be used to using an 8" for their enviroment. did the person have a 150+ gal tank?

Sounds to me like your starting out, and with a 55, 4" is the recomended across the board.