Re: Friend gave me a Beta pet
Betta's are great community fish, despite them being nasty towards each other. They are pretty peaceful most of the time and should get along great with the fish you already have in the tank. I wouldnt put them in the tank together because he will try to mate with her constantly and they will end up fighting or he will kill her by tiring her out. Since you already added the male to your main tank, I would keep him in there and get something else for the female, either to live alone or another community tank. At least a couple gallons and a heater would be excellent.
As Aquaman stated, avoid fin nippers at all costs, they will chew him up alive and he will never have those long flowing fins again