Yeah, I'm pretty diligent about testing. Params are pH 8, Nitates are undetectable w/ Elos kit, PO4 is .03, Alk is 10, Calcium is 415, Mag is 1400. I always turkey baste the tank and I have two mp40 vortechs, so flow is pretty good. Had great growth for the first 9 mos, and then one colony after another started to show the symptoms. Basically, the edge of the smear (the base) would start to almost curl upward. Then, it would begin to lighten up along the curled up margin. Then I'd notice little necrotic sections in the base that would slowly creep up the corals branches. Eventually, it will kill the entire coral. I know it sounds kind of AEFWish, but I'm 99 percent sure it isn't. I've dealt w/ them before in other tanks, and I don't see the telltale bite marks or eggs anywhere. Just necrosis. I'm afraid its a bacterial infection. Sorry for the long post and thanks for the thoughts and ideas, please keep the conversation going. Any more insight would be helpful. Oh, btw, I have a standard 120 gallon.