I don't have clowns in there anyways...I don't think I'm gonna get any clowns, but I will take the advice and pick up a few yoyos pretty soon, and yes, overfeeding is a possibility, I try to feed 12 fish enough and in the frenzy, a lot falls to the bottom....the snails also hav4e plenty of algae to eat (not sure if they eat it or not, but I thoguht that might be a cause too)