Betta Sorority 1 very aggressive girl

I have a 10G which I turned into a sorority tank. I originally had 1 female then bought 4 more. The original female I expected would be territorial, she had already been with guppies and didn't mind them. After introduced the new 4, the original girl showed. Aggression.
I took her out into a plastic container left her floating for a day then tried 2 more times to intro her and she goes back to patrolling the whole tank & harassing,

I know flaring and some chasing is normal but when I intro the original girl back, and she starts patrolling, and she comes into contact with one specific girl she is confronted and both flair and start actually fighting, once I remove the original female the tank goes back to normal and there is very little harassing or chasing.

Should I leave the sorority with 4 girls only? And remove the original girl for good? Or is there some way to reduce her aggression?

 

So, with a betta sorority they should be in a minimum tank size of 20 gallon. A 10 gallon is too small not only because of bioload wise but because females can be just aggressive as males and they need their territory otherwise they will fight since there isn't enough room for each betta. I suggest you get a 20 gallon tank otherwise rehome the bettas.

With betta sororities there is a establish hierarchy and there will always be an aggressive one or dominant one. SO if you remove the aggressive one a new betta will step up. Again the betta above is being "very" aggressive since there just aren't enough room.

 

She might also be aggressive because it was her territory first, and now there are "intruders". Removing her and adding her back later isn't helping because it's still the same territory to her. I agree that a 10 gal is too small. If you can't upgrade to a 20 gal long minimum, I would rehome all but one betta.

 

I'd keep 2 girls and do a divided 10G, but that's just me.

 

Guys When I remove the original girl the other 4 show no issues. Is it possible to just reduce the sorority to 4 instead of 5, until I get a larger tank?

 

You can, but the bullying might start with another female soon and you'll have the same issue.

 

Thank you all