ywllow tang in QT

[BigJim]

I purchased a yellow tang and have had it in my 10 gallon QT for 10 days now. It's been eating seaweed salad, flakes, frozen shrimp, just about anything I put in the tank. Today noticed a dark yellow/mustard patch (about 1 inch) on the top of his head. It is darker than the rest of the tang. I'm not sure what this could be. Any thoughts?

 

[ledford1]

I don't think I've seen anything like that. Maybe it bumped its head?

It would be great if you could get pics.

 

[BigJim]

After looking really closely I see the dreaded white spots. I think the discolored head is secondary due to the ich. I treated the QT with coppersafe and maracyn II. Now I guess I'll wait.