Powder Blue compatibility

[asylumdown]

I bought a skinny but alert powder blue a while back. It was at least nibbling pellets in the store so I was confident with some TLC in quarantine I could get it back in to shape.

I knew I was taking a gamble because my tank is beyond peaceful, there is exactly zero aggression between any of my fish because I don't have any aggressive fish. I know these guys are on the more assertive side, but I have no other tangs, a powder blue is on my bucket list, and I don't know if I'll have a tank big enough for one again for a long time... so I did it.

He came out of QT today. He's still skinny, but he's a great eater so I'm sure he'll fatten up rapidly.

My problem is that within 3 hours of going in to the tank, he'd full blown attacked my copper band butterfly twice. Like, chased across the whole tank I was afraid blood would be spilled attacked. I was fully expecting a little competition between the PB and my doliatus rabbit since they eat the same kinds of food, but I was really caught off guard with the aggression toward to CBB

Is this something that I should expect to die down, or have other people noticed a particular hate on between these species in the past?

FWIW there was some posturing between the rabbit and the tang, but seeing as the rabbit is more than twice the size of the tang, it was a little like watching a punk teenager try to throw rocks at a tank. The tang backed down each time.