My corals started to look really upset. I just shrugged it off as a bad day thing. Then I saw another coral do the same. My worry rose a bit but still, another bad day. Then my Duncan started to shrink and I knew, something is wrong. I started with Alk, 13.8!! I don't have the means currently to do a massive water change. I read somewhere that I could use white vinegar to settle the Alk down a bit but that makes me nervous because I have no real experience messing with anything like that.