I've only tried out things after this problem stared...NAV, I have noticed over time that you seem to be always adding something or changing the lights.
I'm very positive its some bacterial infection. I dipped my trumpet coral and it stopped dying for couple of weeks (scoly stopped dying after Alfred dipped) but now I'm seeing some slow tissue loss again in the trumpet, which is why I just ordered Iodine. So I'll now dip in Revive then in Iodine.Also one thing to consider in my experience acans can get infections. Best thing to do is to cut them back past the point they are melting. Then give them a good dip in providone.