What level of substrate is good?

[chicap29]

I have to reset up my tank because of my underwater filter. I'm going to take it out but have to remove all my LR and fish. Right now I have about 4 inches of crushed coral on the bottom, but have heard that you only need a finger nails depth.

Any recommendations? Should I use anything else other than Crushed coral?

 

[framerguy]

If it's an option and you're taking the old stuff out anyway, I'd replace the substrate with sand, you could mix some of the old CC with it. CC has a tendency to pack and can cause nitrate problems, which for a FO tank may not be a real problem, but for a reef it can be. Plus, sand just looks so much more natural. The depth depends on what you want to keep, and what you want it to look like. If you are going to have sand burrowers you need about 3 to 4". Otherwise I like two inches for astetics. Sand is also easier on sand lifter gills.

 

[ninjataco777]

i have a biocube29 and i have 20 lb. live sand

 

[vdituri]

I have heard the 1 lb per gallon GUIDELINE. It is not an absolute.
It seems to be working for me. I added a small amount of crushed coral to it to help stabilize it from being windswept by the powerheads.