Has anyone used black substare?_ I have painted the back of the tank black and the bottom as I wasn't going to use a substrate._ However my family likes the snails and all that come out of the substrate at feeding time so they are wanting me to put a substrate in it._ I am thinking of black as I like the darker back and bottom as it doesn't take away from the brightness of the corals and fish like the white does (at least I don't think so)... your thoughts and pics?