So, I have some female bettas. I had kepts a group of 4 in a 10 gallon. I read that you needed to have at least 4 because if you have 2, one will pick on the other, if you have 3, two will gang up on one. I read that 4 was an ideal number. So that's what I did.
This is what I found out, the littlest one kept picking on ALL of my other fish. I took her out and the other 3 got along just fine. Unfortunately two of them had too much damage, never fully recovered and died. :(
So the remainder of the 3 is recovering on her own in the 10 gallon. and the little girl is back in my 2 gallon alone. This is my interesting observation.
Apparently, bettas like warm water (around 84, right?) well my bigger tank, is set to 84 and the betta is fine, loves it. My little betta, in the 2 gallon, gets really lazy and doesn't move much at that temp. Bring the temp down below 80 and she's swimming around enjoying herself.............why such a difference?