I have two Ocelarus Clowns for a couple months. They are fairly small. Since I got them they hang around the two black return tubes going into the tank at the top of the water. Is there anyway to get them to come down and join the rest of the reef? I was hoping my new long tip leather would entice them, but no luck so far. Also, will they always stay up there? or will they move down when they get larger? Is this common?