Too deep a sand bed/live sand or not?

[s1214215]

Is there such a thing as too deep a sand bed. A friend of mine just set up a DSB (8 inches deep) in a FOWLR system. I wonder if its too deep. The tanks is a 550 liter system. I run a 7 inch bed in my refugium and its great.

Also, he used oolitic fine sand from a local mangrove/beach area, taking the sand from the top layer and from sand that would be covered during high tide. This would be live sand right? Will this speed up the cycling of the tank much or is that a hard one to call?

[Ninong]

Is there such a thing as too deep a sand bed.

No.

A friend of mine just set up a DSB (8 inches deep) in a FOWLR system. I wonder if its too deep. The tanks is a 550 liter system.

Eight inches is not too deep. One of the people who has been promoting DSBs for several years recommends a minimum of 6"+. Inland Aquatics has run several experimental tanks with DSBs twice that depth.

Whether an 8" DSB is oversized for a 550 liter system is a matter for the hobbyist to determine. I have a 6" DSB in a 450 liter aquarium at the moment and I now believe it is a bit deeper than it should be for such a small tank.

There are lots of reasons for avoiding such a deep sand bed but none of them have anything to do with the viability of the sand bed itself. I know some gorgeous 600+ gallon reef tanks that are running with very deep sand beds and others that are running with no sand beds at all.

Also, he used oolitic fine sand from a local mangrove/beach area, taking the sand from the top layer and from sand that would be covered during high tide. This would be live sand right?

Yes.

Will this speed up the cycling of the tank much or is that a hard one to call?

Yes, it will speed things up but this is never a real problem to begin with. Even if you start out with plain ol' dead sand, bacterial populations will begin to colonize it immediately and denitrifying bacteria grow extremely fast in response to available nitrogen.