Why do my clownfish keep jumping out of the tank. I have a 29g biocube, and everything is fine with the water, and everything is thriving and happy, but one of my O clowns repeated jumps into the back, I find her on the grate in the middle, laying there, who knows how long shes been there for, as im at work all day. Sometimes she gets lucky and gets in one of the other compartments that actually has water in it. My other one has done it once or twice, but she does it every second day!!! Why is she doing this, and what can i do about it?