no you dont have to feed him clams ,where did you here that baron ,mine simply likes brine shrimp and i soak it with garlic to prevent ich which is very likely to happen and it might be what is wrong with yours which you probably know what ich is but, i dont think your tank is over crowded either just keep watchin your butterfly, and ask questions all u need, oncee it gets better u will love ur butterfly... and u might want make sure ur protein skimmer is workin right and u might want to look up some info on uv sterolizzers because i saw on petwarehouse ur suppose to get one i think im fixing to