rusty coraline?

[Myka]

I don't think there is anything else you can do. I'm not sure if removing the infected rock will help...not sure if the pathogen would be infecting the water column? Personally, I would just let it run its course, and maybe in a few months/year who knows it will start coming back. I wouldn't take drastic measures to be rid of it since no ones really knows hoe to get rid of it anyway, so at best you're just taking a stab at it.