Mmm - and I don't know how long he's been doing that because until today he's been completely hidden behind some slate and in some plants, today he has ventured out into an area that is slightly more open, so I noticed his mouth, I'm gonna worry about him now!!Its the opening and closing of the mouth, if he's doing it alot its not normal.
I think there is something going on health wise with him.
Sadly I can't isolate him, I only have the one tank and I'm at work tomorrow so I can't have a good look at him til later. i will do the 20% water change when I get home tho, maybe that will help?Welcome to fishkeeping, not nice at times, i worry, just keep a close eye on him, is it possible to issolate him.