Does my tank have the ich?

[AJ_77]

Good maintenance and proper feeding are probably the best things you can do right now, as anything major or drastic will put more stress on the tang. A steady, stable environment is as important as anything right now.

But I'm just echoing what others have said before - keep up the garlic and nori, and water quality. I haven't kept tangs (they make ME nervous), but as with other so-called "delicate" fish you have to provide the optimum environment for them to be healthy enough to lick it themselves.

As to your buddies - not your fault. They're responsible for their own behaviour.