[Potatohead]

I purchased a yellow eyed Kole tang about 2.5 weeks ago. I observed this fish before purchasing for at least twenty minutes, as well as other fish in the tank, but you can probably see where this is going.

Long story short, the fish passed away yesterday from what I believe was ich. After a few days in the tank it developed a few spots but fought them off and was eating very well so I figured it would be ok. Then about a week later it was covered worse than before, although still eating and seemingly ok. It died 24 hours later.

So now, I don't really know what to do. I don't know if the ich was already in my tank or if it was on the kole. My other fish show no symptoms I had never seen any until the kole. He did have a golden sheen which could have been velvet I suppose but the only place was on his nose in a small spot. Tearing down the tank and going fallow for ten weeks just isn't going to happen. I don't know if I should just forget tangs altogether (which sucks), try another one, wait a while and try another one, try a different fish... I just don't know where to go from here. My bioload is pretty light and I was hoping to add a hawkfish and maybe an angel along with the kole until this recent development.

Thanks for any advice.