Adding to a sorority

[CLCDiver]

I just established my first ever betta sorority. 4 females who were all introduced to the tank together (first given only visual access to each other, then allowed to explore freely). After a few days of chases and a bit of fin nipping they had settled down quite nicely (especially after adding some rasboras, which seemed to distract the bettas from each other).

But I'm currently fighting an attack of columnaris, and have already lost two of my females. The two remaining females aren't bothering much with each other, but everything says you should not keep only 2 females together. What I'm wondering is what is the procedure for adding new females to a tank with existing females who already have staked their claim on the tank?

(Of course, this is assuming that the treatment is successful and I wouldn't dream of adding more fish until the tank is healthy again.)

[LebronTheBetta]

First off, I'm so sorry you're tank has had an outbreak. :( Best of luck to you and your remaining fish. Sorry for all the losses..

What I've heard, you're supposed to move the decorations around to different places in the tank. That way, you can start all over with the new females and current. And to let them acclimate to the current ones, you have to float them with each other. Make sure they see each other and the floating intro is supposed to last 2-6 days.

[ChoclateBetta]

Yes move the decorations around but also figure out what led to the outbreak.

[kfryman]

When I added one of my girls afterwards, my girls had no problem adjusting with her, just nipped fins. Didn't move anyone out or rearrange do to live plants, which take forever to rearrange.

[ChoclateBetta]

You had one of those rare cases.

[aemaki09]

I just added to my sorority without moving decorations or existing fish today and have no problems with any of that, they are trying to establish a pecking order with flaring and what not, but arent really nipping or chasing too much. Maybe I just got lucky and have all calm females?

[ChoclateBetta]

Some people have success with what is not reccomended. Glad it worked out.

[Xeek]

The EXACT same thing happend to me. Except I went from 6 females down to 3, and then the 3rd one had to be moved to another tank and also died of infection.

The remaining to bettas seemed to get along perfectly for several days even shoaling some. Eventually one began to pick on the other and the less aggressive one got nipped nicely.

My theory is after the most aggressive female or both females realize they are the only two in the tank and the other females are gone, that is when the aggression balance is knocked off kilter. Without more bettas to spread the aggression around one betta will pick on the other and no other bettas around to keep her on guard.

The trick is to have bettas that want to attack, but rather than attack they're more distracted about being on guard with other bettas around. That's the theory around spreading out the aggression.

After several days you may noticed a problem. I recommend buying some more girls like I did. I started over. I'm now back up to 4 girls in the tank together. It's a 16 gallon so I bought 3 more girls which are in holding tanks. I don't add them to the group until the stress from transport and petshop tinkering has gone down and they are comfortable.

[ChoclateBetta]

I think with less in the tank avalible room was too much and they did not know how to get along and the weaker one was bold enough to invade and lost.

[Xeek]

They have such complex personalities. Moving decorations around and all that is probably best if adding one to a sorority. If you add more then one then moving things around isn't as necessary.