what kind of fish are you getting? if your planning on diggers you might want to put the rock in that you want as a base first then put the sand around it. i did that when i set it up and glad i did cause of my engineer gobies. some diggers can collapse the rock if its not stable. just use aragonite sand and go with at least 3-4 inches some have gone with 5-6 or deeper but thats jsut the tank owners preference. dont bother mixing it with crushed coral it gets to be a pain and always rises to the top i did that at first and ended up sifting the cc out. i wouldnt go with gravel not only will it break down but there may be minerals in the stone you dont want in your aquarium where saltwater will pull those minerals out and fresh water wont _________ karla  75 gall, 80 lbs sand, 110 lb lr, 10k pcs, atinics, emperor 400, prizm skimmer, hagen and maxi jet powerheads |