Yea he's been kind of moving between two spots on it. But low light on the bottom would probably be a good place for it instead of mid way on the tank? I read somewhere that if they get a little more light their tentacles will grow thicker, but if they get less light then the body will get wider and tentacles might grow a little more upwards. Not sure how much of that is true being that I don't have any experience with corallimorphs at all. Also, can they be fed mysis shrimp. That's what I feed my clowns so that would make things easier.