Is my tang turning into a zombie?

[piusma]

The reddish area could possibly be cause by ammonia. How many gallon is your QT setup and have you changed water since it's been in there? You need to stay on top of water change because this tank is most likely not cycled yet. I'd suggest you to do 30% water change for the next 5 days. That should improve on the water quality. And you should start a filter running for the tank. (That probably won't be effective for another 2 weeks or so and during this time you should do approx 20% water change ever couple of days)

Similar situation happened to me when I first started and I had a QT setup to help my fish. I had 3 fish in there and my yellow tang didn't make it because of the poor water quality. Now I run a much better QT / hospital tank setup to deal with things.

Steven