Not sure what's wrong. He's had this for almost 3 weeks now. Developed a couple weeks after putting him in my tank. My readings are 0 across the bored and no other fish are sick. I'm still hoping it goes away on it's own, I don't like to medicate my tank. Anyone know what it might be? The spots are uniform on both sides of it's face.
That`s what I think it is. HLLE can be caused by stress or vitamin defieciency. What size tank is he in? Tangs in smaller tanks have seen HLLE more often than those in bigger tanks IMO. Read the following links.
Doesnt make any difference on the size of the fish. But IMO a yellow eyed Kole tang should be OK in a 72 gallon tank. When you said holes in the head it`s probably what it is. All those white spots are on the face and lateral line.