Whatever you do, do not add just one female betta in with a male. He will most likely harass her to death. You will need to have a good sized tank and lots of females to go with the male.

Usually you could add any fish that is not too agressive and does not have long flowing fins with a betta. Male guppies could be seen as a threat by the betta because of their long flowing colourful fins.

Dasheen

Hi Dasheen,
Well if I added 2 or 3 female Bettas to the one male Betta and 2 cory cat fish. Would that work? Along with lots of plants to hide. For some reason I have been reading that Guppies and Bettas blend well. But either way I do not want to get guppies. When I was a kid, I use to raise them. I remember the male guppies use to go after the female guppies relentlessly. Now, I just want to try new types of fish.
Theresa

you might want to use silk plants or real ones instead of plastic ones becuase the betta(s) might tear their fins on the plastic plants.

Do not mix the male and female bettas. The male will be stressed from the females harrassing him. Don't put guppies with the bettas either; their flowy fins are reminiscent of a betta's, and either can attack.

Bettas, especially males, do best by themselves. A group of cory cats will do okay in a 10 gallon, but you'd probably want to stop at 5 cory cats, 1 betta, and plants. That leaves plenty of room for your cories and betta to grow, and lots of clean water. You could add a snail, but bettas can and do kill snails.

Here is a link that might be useful: This is what happens when a males and a group of females mix.

I lost my beautiful male Betta from the harrassment of a female Betta. Even with plenty of plants to hide in. I now do not have any Bettas. I also had a few Cory fish then.
Theresa

What about one male betta with two female, four to six neon tetra, two snails, in a 16 gallon?