Can anyone tell me whats wrong with corals in my tank. PH 8.2- 8.4, ammonia 0, nitrate0.5, nitrite 0. My corals don't seem to open. Mushrooms shrivelled up, polyp's only some opening a little bit and now the rock that they are on is breaking up, xenia shrivelled up and died although 2 camel shrimps or a dragon wrasse may have been responsible for that. I am using ro water with kent sea salt at 1.025 approx. They used to look great but now look terrible. tried a new bit of a mushroom coral that looked good for 2 days then it went the same way. Can you help me get to the bottom of this. I am fairly new to hobby. Tank 30 gallon is about 9 months old now. About 30-35 Lbs LR. Shallow livesand bed. Berlin skimmer. Powerhead.