Would the hard corals I put in the tank cause my carbonate hardness to keep dropping. I check it last Thursday before I went out of town, and made sure it was up to 11, and Sunday when I got home, it was down to 7. What would cause this to happen. I have been keeping a close eye on this, but a few months ago I added some hard coral (rocks), to my live rock and now I seem to be having trouble with the water. If the coral is causing this, then I will just remove the coral and be done with it. I have notice the pink stuff growing on it though. So, something must be good in the tank.
All other tests are good. The fish are doing very well. I want to get a new fish, but need to find out what's going on with the carbonate hardness first. Thank you!