fin nipping

[reef tank 2.0]

I have 3 banggai cardinals in a 20g QT. They just got past their first week in the QT, 3-5 weeks to go.

I noticed the smallest cardinal of the three is getting nipped. two of his fins are a little tattered.

Will this behavior stop or should I place a tank divider in the tank? I can't exactly take any of them out and place them in the DT, and I also don't have another QT just lying around.

Anything I can do to help this issue? Will they always do it even when in the DT?

 

[3dees]

it's what they do. best to get a bonded pair. sometimes a small group can get along, but most of the time you will be left with one, maybe two.