On top of the heater issue, seems like lots of things were being changed, salinity fluctuation, temp fluctuation, which invariably would have changed the Alkalinity slightly too, up and down due to salinity fluctuations. Then, we change massive amounts of water, then add carbon, and wallah, we are now sending our corals and inhabitants on a roller coaster ride. Knee-jerk reaction will in fact cause further loss, sometimes when rtn begins, for whatever reason, it becomes a plague, moving from coral to coral. I have experienced it, and for no understandable reason. I would most certainly pull the heater, and run carbon, albeit, per recommendations and introduction via reactor on slow effluent, ramping as you observe coral polyps, being my # 1 indicator. Suspend any dosing, calcium reactor, or kalkwasser, likely your corals will not be using, thus an increase in main minerals. You may want to adjust the photo period and intensity, as this may too cause the corals further stress. When things go wrong, or when we take on new products, it is always wise to do so one at a time, trying to isolate and get to the root cause, that or seeing how new changes are impacting color, growth, and pe. Try and stabilize the system, ensuring big 3 being stable, as well salinity and temp. I would 100% do an ICP analysis. My thoughts
Fingers crossed for your reef!
Fingers crossed for your reef!