We have a pair of clowns who do breed, but we have not been sucessful at hatching the eggs. Here's what to look for if your clowns are ready to spawn.... First, the female is larger than the male. Her tummy will bulge because she is full of eggs. The male, who is smaller, will begin to clear the algae off a section of LR and get it ready for the eggs to adhere to the rock. When spawning is about to take place, you will see a clear tube protruding from the underside of the female. I have heard some people say the clowns will not lay their eggs while they are being watched, but ours will do it right in front of us and it is fun to see. The female will deposit her eggs in a line then the male passes over the eggs and fertilizes them and the the female deposits another line of eggs and back and forth they go until all the eggs have been laid.
If you don't see the male and female going through this ritual any time soon, then your fish are just eating too much. Do you have pics?