u/sincerely-baffled

Does anybody know what this is?? I just noticed it yesterday I thought he had like a piece of food stuck or something but it’s not gone away. He’s still eating, seems to be in good spirits. Water is at 0 ammonia, 0 nitrites, and 10 nitrates. Recently added some Anubias plants….just unsure if I need to address anything right now.

I’ve got some new fish in the quarantine tank already awaiting the clear for the main tank…dunno if I should move him there?? Idk. Helpppp, please.