Originally Posted by xjenuhfur
A 10 divided 3 ways can work. Or you could do a sorority. :)
2 ways or 3 ways works, I have a female betta who is SUPER active, so I was going to only divide a 10 gallon tank into two... Be sure that you quarantine all the bettas for at least two weeks before putting them all in the divided tank, if one turns out sick it can spread to the others. Also be aware bettas like to jump over dividers, so you need to lower your water level or extend the divider to the top of the hood.
And sororities are difficult to manage and a lot of work, I wouldn't do that. I'd just get a divider.