Hey Everyone, So I woke up this morning to see my xenia looking like it is starting to melt. Yesterday it looked great. It is actually spreading to other rocks within the tank! The only thing different from this time yesterday is I added a new powerhead to increase flow in the tank (not pointed at the xenia at all) and I dosed the tank with 3ml of Kent Marine, Marine C for a tang that had some spots. Parameters are as follows: PH - 8.3 Ammonia - 0 Nitrite - 0 Nitrates - 5.0 Calcium - 540 KH - 179 Temp - 80 Salinity 1.021 (clearly need to take this up slowly.) Any ideas???? All other corals look fine!