As many people know, male bettas (Betta splendens)cannot be housed together, or else all heck will break loose. Well, most people do not know that it is possible to house females together--when done properly. If it is not done properly, then the girls act like the boys.

Here's a quick "How-to" for setting up a basic female betta sorority tank:

A sorority tank should not be less than 10 gallons.
The stocking is no less than 4 females and up to 5 females per 10 gallons. This is so that the girls can setup a pecking order.
You'll also want to try to keep the plakat girls with plakat girls. Veils and other tail types (excluding plakats) are better to house together. The plakat (PK) girls are typically more aggressive than other tail types, which can lead to problems in the future.
Provide as much cover and hiding spots as possible. The females will not only establish a pecking order, but will also setup their own territories. The dominant female will always get the best spot. Keep in mind that you'll want to add the females to the tank at the same time. Each time you have to remove a female for breeding, medicating, etc. then everything in the tank will need to be moved around, or more fighting wll occur because the removed female will have lost her territory.

Now, the reason PKs are not recommended to house with other tail types is because PKs are more aggressive by nature. They are the tail types that are closely related to the fighting PKs still used for fighting in Thailand. (For example: If you were to put a HM in with a fancy PK, the PK would rip the HM to shreds with no problems. Long fins are whimps compared to fancy PKs--the longer the fin, the more whimpy the fish.)
I just have learned this lesson sometime ago. I had even read a post by someone else on another forum who had also learned this lesson, as my mother has told me since I was a teen, "You have a hard head!" Well, I guess Mom was right about that.
Any way, I had a 10 gallon sorority tank that I kept my potential breeders in (a few I have tried to breed, but I made a big noob mistake), and in that tank are 4 PK females and 1 HM female.
Well, I went to do a water change, and the 4 PK females swam up to the gravel vac, but the 5th was missing. Just as I started looking for her, she came swimming slowly from the back corner of the tank--chewed up and displaying stress stripes. So, I quickly grabbed a fish bowl that I had empty and seperated her.
She didn't make it. She had died of injuries, stress, and body fungus that has set in on her wounds.
Her caudal had been chewed down to the meat, and she had most of her dorsal and her anal fins chewed off, and she had a few bite marks on her body.

Definitely lesson learned.

Very imformative post Do you have any pics ?

Let me dig through my pics. I have since torn down that tank, but I am setting up another sorority.

These are crappy pics, but you aske for it. I think there were taken with the ol' camera phone.

At the time of tank tear down, I was starting to have diatoms build up every where, but that wasn't the reason I tore down the tank.

Right Side of Tank:


One of the Girls:


Wow. That's it? I'll see if I can get more pics up--if I have them.

Here we go!

This is the first layout of the sorority:

I did not think the pics were that bad So if you are setting another one up how about keeping a photo log, and then sharing it with us ?

I will, sort of. So far in the new sorority, I have in substrate, driftwood, a light, background. I still need a filter, which is why I haven't put the girls in. I guess I could go take some pics. lol

Yes pics are a good idea You know me i love to see pics of other peoples set ups