Quite a few years back I had a 55 gal FOWLR aquarium with around a 4" sand bed. I want to get into it again but want to stay simple. FO is what I'm thinking. What substrates are recommended for a FO tank with no live rock, just a few decorative corals. I know CC used to be a big "no-no" is that still the case? What does everyone recommend? Thanks!!