Female Betta is Missing a Large Chunk of Fin.

[Salieri]

So I came home from a walk today, and one of my female betta's fins had a huge chunk out of it. I was gone for about an hour and a half, and she was fine when I left. I'm assuming there was a bit of a fight while I was gone or something, but they're usually very peaceful from what I've seen thus far.

Should I quarantine her while it heals? Or do I just leave it, and hope she doesn't get hurt again? Would there be issues with the pecking order if she was removed for a bit?

Thank you.

 

[Candilion]

If you want to take her out so you can keep a closer eye on her while her fins heals you can. Just as long as you reintroduce all of the other bettas to your tank at the same time. It kind of evens the playing field they all kind of think they're new fish in the tank.
If you don't want to remove her I would keep a very close eye on your tank, I've read that female bettas in a sorority can change the way they feel about each other at any time in their existence together (especially when maturing).

 

[Salieri]

I was watching the tank, and one of the most docile of the fish, maybe even the most docile actually, started attacking her. I guess they suddenly just rethought each other or something. I move her into my backup tank until she heals, and then I'll reintroduce them all at once again.

Thank you!