All levels in check as far as the usuals go. My acro colony has 2 branches that are turning white. My monti cap has a white spot right in the middle of it about the size of a dime. This is just over the course of the past couple days with the monti, and the acro just today wham 2 branches with white. Just tested my calcium, at 400, I need to dose. 3 days ago, my ammonia tested at .25 but has since returned to 0. sal 1.025. All my other corals are good and these 2 pieces have been in the same spot forever.