Bettas & Community tanks

Question
Hi, Karen,
I have just recently bought and set up a 20-gallon tank that I'm hoping (HOPING) will hold one of my male bettas (I have three) and several females, among other small fish such as neon tetras and the like. The male I'm planning to put into the tank is relatively large and very tough, but as far as I can tell, pretty calm by nature - he has only flared once at one of my other bettas, and it was very much in a half-hearted "he started it" manner (he also flared once at my cat, which was incredibly endearing). The other possible male is more skittish but doesn't seem to flare at anything. And I have one girl so far - she has a very nice disposition.
The tank, as I said, is 20 gallons and has an abundance of foliage and places to hide. I've been reading up as much as I can on the possibility of housing males with females and I know females need to have enough of them to establish a pecking order, but that males will almost always bully the females. My question would be whether or not this is something I should even attempt - the answers I can find seem to vary between "try it and see" and "don't try it at all". If I do just need to attempt a trial and error, would it be better to try with only one female, or three or four?

I also have another question, concerning my third male, who is a small crowntail that insofar as I can tell is suffering from Swim Bladder Disorder. He's tucking himself against the outside of his bowl to keep from floating up onto his side, and he has a large bulge just behind his head and seems to be a little less than sleek towards his tail. The size of the bulge almost seems to get larger and smaller as I've been keeping an eye on him. I tried fasting him for a few days and then fed him a piece of pea, and within minutes he had had a bowel movement and the swelling had gone down. But then the next day, it was back. He got much better for that day, but now he's back to the way he was before, and I'm very concerned. Is there a specific medication I ought to use on him, or should I take certain steps to help him recover on his own, or is this something that my betta and I are just going to have to live with?

Answer
Hi Megan,
You can always try to putting the male with a females. But most likely either the male or the female will be too aggressive. Usually the male will attack any females around viciously. The only ways I've seen this work out is if the tank is heavily planted with plenty of hiding places and if both fish have relatively good temperaments. Sometimes they can get use to each-other but most of the time they cannot work out peacefully.

Unfortunately it is trial an error situation. You will have to wait and see how they do. Watch them closely for sings of extreme aggression.

I'd imagine with your crowntail that he is in fact quite prone to swim bladder disorder. I think all he needs is to have a diet change. First I would fast him as you did before and feed him green peas. And then I'd hold off all his normal food for at least several days. Consider his diet, if he is on pellets, try presoaking them before feeding and make sure not to give him too much. Try giving him variety in his diet also, try giving him frozen foods like bloodworms, brine shrimp, and others. Give him a little bit of green pea at least once or twice a week to help prevent Swim bladder disorder.

I really hope this helps!
Hope your betta gets better,
~Karen