So I had my black paradise fish in my display for about a week now. Did put him in QT for 3 weeks and he was fine.

But now, I see something on the top lip of his mouth. It's a little bit white, but not like cottony so I am not sure if I should treat or not. Because it might be a little bit hard for me to catch him in a 100G with tons of hiding places...

I just noticed it yesterday so I ain't really sure about it.

attached are the pics. If you can just focus to his mouth..