Whats happening to my corals?

[michika]

Sadly there was no spike that I found, and I test once or twice a week. I've watched my tank for hours since the initial change over and I haven't seen anything from the angels that ressemble picking at the corals.

I just can't think of anything that could have caused it. There is no constant between situations as to why they are dying off. I haven't added new rock or anything that could contain hitchhikers. The only thing that has really changed is that I stopped dosing liquid reactor at night.