i am not sure, but a tank full of female betta's are called "sororites" (just saying) , all i know you cannot keep alot together, the less females more aggrehesion between them, i have a 5 gallon but it seems small i would suggest 3 because you cannot keep 2 together (thats what other people say not me) because they will bully one another, i had an betta, algea eater (R.I.P), and a glofish together in a tank and they where somewhat fine (until i got a 27 gals), IF you have some money i would suggest a 10 gallon, people say it is more proper for the females
am just saying
definitely wouldn't try a sorority in anything less than a 10 gal.
5 girls are recommended as the minimum number, and anything smaller than 10 gal wouldn't be large enough. You also need lots, and I mean LOTS of plants and hiding spots, ideally you don't want to be able to find them.
Definitely not a good idea to try a sorority in a 5 gallon. Typically, you need 4 or more females to make it work (with 3, you run the risk of the dominant two beating the omega to death then turning on each other, and two will rip each other apart from the word go). Whilst females don't need territories of their own, per se, they do need space to get away from each, especially after a fight, which a 5 gallon simply does not provide.
A ten gallon or larger is the way to go. :) I have six females and some other fish in my 16 gallon.
oh wow I feel stupid that I even hoped that would work.......
seriously don't feel stupid! What's important is you asked, and there are perfect alternatives to starting a sorority tank : ). honestly you could set up a really nice tank for one betta with some shrimp to keep him/her happy. Don't feel discouraged, everyone here just wants the best for you and your fish, and the advice is to avoid the least amount of headache and heartache for you.
if you really really want to start a sorority, check on craigs list you can often find really nice 10 gal and up set ups for cheap.
+1, do not feel stupid about that. If you still do, look at Yahoo Answers and check out the questions with people asking why their two females are fighting in a 1 gal bowl...
The clever ones are the ones who ask and research, like you have. :)