I've had pretty mixed results. So far almost every piece I've put in there initally bleached, but I never lost any. Since then most have colored up, but not to their full potential. I'm thinking of raising the lights up in the canopy a couple of inches. I'm thinking about this because I've been trying to get rid of a few frags due to space, and in gathering these frags together in the tank I've put them pretty low...and after about two weeks the colors on them look fantastic....