Please help Long nose butterfly

[Reefer902]

I have a long nose butterfly for around a week in my 120gallon. I was acclimated for 45 minutes and he started picking copepods of the rocks the minute he was added.

Strange thing then happened last night and I know this seems strange but when I fed the tank mysis and flakes he started to swim really fast and seemed irritated. Since then he has been swimming backwards, on its side or just moves around all over the front glass as if he wants to get out. The water parameters are all on check and nothing wrong there. He is too quick for me to take a proper picture to try and see if he has velvet or ich, but I do not see anything on the body. I might have spotted some white spots on the tail fin, but I cannot confirm that as a positive because he moves around too much for me to confirm.

Does anyone know why this behavior? I do not have a large QT tank, only a little 5-6 gallon and I am reluctant to try and QT in such a small tank. I do not have the space for a larger QT tank, else I would have just gone and bought one. The picture I took is the best I could do, after than he went to hide between some rocks.

[outssider]

Is he still eating ?....If so, you should be good to go....