I'm setting up a 60 gal rimless 4'x2'x1' deep frag tank. Filtration will be a combination of live rock and an ATS, both in a 20 gal sump. My question is for those who have done Frag propagation before, should I put sand in the bottom of the tank? I plan on having a clean up crew to maintain the sand. I have the nature approach of filtration and feel the sand would be beneficial in many ways. I also know there are unforeseen circumstances. Any help and opinions would be greatly appreciated.