Well, that is good to know. I was concerned that my sps would not benefit from it. I can tell that my monti caps have grown, however, my purple hae monti is turning white, and my sunset retracted polyps. Still haven't used much of it as far as water changes go, but I will cont. to use it for now and keep testing to see how consistant parameters are. My ph in the tank stays a consistant 8.3, which is good.