Female Bettas

I wouldn't risk a male mixed in with females unless it's a big tank that gives the girls lots of room to get away from the male. Females are typically less aggressive, but there are exceptions. Adding some to a community tank is a risk that you get one that will be very aggressive and shred fins. Mixing bettas and gouramies is always a risk, as well--they will still want the same turf.

I have kept a few females in with males, and the male ended up getting his fins torn by one aggressive female! It could happen, but make sure you find very docile females. Females will fight with each other! Not as bad or as often as the males, but close enough.

I had one female in a 29 with 2 dwarf gouramis and 2 german blue rams. She terrorized everyone and she is cooling her fins floating in a bowl in that tank until she gets her other tank back......I'm using it for a young pair of german blues. Right now they're sitting on a batch of eggs in her 5 gallon planted.

I also have a 10 gallon that has 2 female betta a danio and a female guppy. It's my "OddBall" tank. A place for fish that I have to move for one reason or another. One of the females is a monster ! She's a beautiful purple girl but she's very aggressive and quite the hog when it comes to eating. She'll snatch the tubifex worms right out of the ADFs mouth if I'm not there to keep her away when I'm feeding them.

You could keep female betta together but you have to watch them and remove any overly aggressive or passive ones. The aggressive ones will tear into everyone else and the passive ones wont' defend themselves well and end up getting shredded. Make sure they have lots of room and places to hide from each other if they have to.

A good suggestion would be to float them in bowls in the tank where they can see each other for a week or so. They get accustomed to thier neighbors in safety and less likely to tear into each other as badly when you let them out.

Hey I've had a plain betta tank one male and many female before and no one fought so I don't think anything should happen plus I've always had betta and gourami together and they don't fight and I've never had anyone nipping fins ^_^ I'm a yes for one male and 3-4 female, just make sure you have space because female are territorial.

I've got three females together, and they are doing well. (usually, if you get young ones, or sisters that have grown out together, it will work). HOwever, I don't have other fish in with these ladies as they aren't too friendly to outsiders. Some people will put a male in with several females, but it is risky, and you'd want to make sure you had a large tank so that there was plenty of space for everyone to go to their own room so to speak when they needed to get away... I personally wouldnt' do it. Though I am thining of getting a 20 long with a couple of tank dividers so that I can put my females in one part, and males or other fish in the other parts.

Emily

Edited to add:
Just because you see certain fish together in the LFS (or a bunch of the same fish for that matter) doesn't mean it's a good long term solution. It just means the fish won't immediately kill each other. In a LFS, tanks are often over stocked, but also over filtered, and hopefully over maintenanced. Often, fish that get along O.K. or even school as young ones will fight when they get older, so it is best to keep them one to a tank, and lastly, because the fish are changing all the time (old ones get sold, new ones come in) there is much less chance for any one fish to establish a territory or dominance over the others, wheras this could easily happen in a more permanent tank with little change in tank mates. And, if we have a fish with us for too long (usually this is our south american cichlids, but it could be anything) we sometimes have to remove a bully from a tank, and/or put fish that have been beaten up into a hospital tank.