Tang and fish issues.

[Nick32]

So...over the last month or so, my tank has been going downhill, I've already discussed my coral and anemone problem I had earlier on the forums and you guys really helped...but for those who didnt read my posts...ill recap...about a month ago I noticed my mushroom corals were "disentegrating" and my anemone was shrinking and not extended...After trying water changes and replacing the lightbulbs I decided to move all the corals out of the tank, and the anemone as well. I moved them to a smaller 33 gallon with T5's over it, and they made an immediate recovery, all looks great now, and the surviving mushrooms are completely recovered. The mushrooms that weren't movable and remained in the tank, are almost completely gone and are no more then small fussy white frillies. Then I started noticing issues with the fish...I lost my bicolor blenny almost right away and with very little warning...everything else seemed fine though...today I noticed red "blotches" on my yellow tang that would appear and disapeer as the days went by...I read that this could be a bacterial infection...also, my clownfish and my powder blue tang appear to be getting frailer, and I noticed that my PBT had lost some weight, as I could see his backbone barely protruding through his side. All the fish are still eating very well though. I've also alot of rubbing and itching on the rocks...and alot of cleaning by my two cleaner shrimp has been going on...all inverts seem unaffected by whatever it is...Whatever it is, it started with the anemone and mushrooms...and now it seems to be hitting the fish, I'm pretty sure it killed my bicolor, but I really dont want to lose my yellow tang or PBT.... Please help!