I Cannot tell if this is fin regrowth or ick? My pictures are not that good. (Possible ick is on tail, dorsal fin. Also the last picture has a brownish patch, what could that be?
It could be Ich but I'm not sure because the pics are blurry.If it is Ich,I recommend vitamin like selcon added to the food.The brown patch could be hyper-melanization which is basically scar tissue from being stung by a coral/anemone.
If it is Lymphocystis stuff (like on the tangs fin) How should he be isolated? alone in a seperate tank, a little birthing tank type thing. Should he leave the current tank so he doesn't cantaminate it?