Mysterious disease: what next??

[peppermint22]

Hi! I've been reading on wetwebmedia about fish diseases, and I find it rather difficult to tell the difference between Brook and Velvet.

 

BTW, my royal gramma recently died of some sort of unknown disease where it seemed to start with ick, subside and contract a different disease, this time like little holes in the head. When the gramma was still alive, he constantly scratched himself on the sandbed. (the gramma had suffered like this for almost a month B4 he finally came to R.I.P.) Now, after his death, the clowns have taken on a whitish layer on their skin and fins too, just like the royal gramma, and one of them is scraping itself against the candy cane coral, trying to ease itself of some kinda itch. Someone, pls help me identify the disease.

 

=(