"i would suggest 2 gallons at least for each fish . if you want a betta get a bigger tank. if you cant, then dont get a betta .

get a feeder fishy"

well no, not per FISH, per inch maybe.. cause some fish can be just a couple inches long, and some are 1-2 feet long. you couldnt fit a full grown koi in 2 gallons of water! lol

as for bettas, they dont need huge tanks. 5 gallons is more than enough for 1 betta.

and I definately do not think youd want a feeder fish. not only are those risky because they are often very weak and carry disease (although 2 of my current fish, and 2 of my past, were feeders), more importantly, they are GOLDFISH. and like I said in my last post, goldfish are a lot of work.