Can anyone direct me to a thread or two regarding this topic? Any suggestions? I have good water quality, weekly 25% water changes, corals like frogspawn and hammer safely away, flow seems good ( 2 koarlia #2's in a 49g corner) 250w MH, 2 actinics positioned 4-10 inches above surface, Remora skimmer, Eheim filter, established tank, all fish good and all soft corals good. Hard corals are turning white, fleshy mucas forming for a day then dying out the next. They make great kitchen window ornaments, but I would rather admire them with the rest of the tank!!