In general, acros are less tolerant of fluctuations in water parameters than other coralsQuestionI just introduced an Acropora to my 65-gallon reef tank, and it’s already starting to bleach on me. I’d say about one-quarter to one-third of the colony has already bleached, and it’s been in the tank less than a week. This is my first acro. Apart from it, I have several different varieties of soft corals and zoa colonies. The fish include 6 blue-green chromis, 1 royal gramma, 3 polka-dot cardinalfish, and 1 lawnmower blenny. All my water parameters are fine, and my lighting (high-output T5s) and water movement are both good. I placed the Acropora high in the tank close to the lights, so I know insufficient light isn’t the problem.