at night or even in the day time. if nothing is covering the bottom of the tank. your going to see little lines and those are the worms, every tank has them
they look pink in the day time , they are safe but you dont want the population to get out of hand. reef safe Wrasse will get the babies that you can not see. their for older ones die off and get eaten some time as while
i have three clown fish ones a midnight. after a couple of week the clown fish give in. if your going to add more clown fish make sure they are same size of bigger to reduce fighting