what is the minimum tank space for 1 betta? I usually see them in cups at the petstore- they told me they dont mind it, is this true? how can they survive in such small places compared to goldfish?

They dont survive in cups, but because they can breathe air then people think they dont need much water which is so untrue.

Theres a difference in minimum tank sizes and some will say a gallon but personally i think 4 gallons is small enough. You will need gentle filtration and a heat source as well.

what do you mean they can breathe air?

I have never kept mine in less then a gal. They are SO much more active in a bigger container then those tiny little cups that they can barely move in, which to me means they are a lot happier. The betta that I have now is in a 5 gal and is always moving around.

Bettas have a Labyrinth organ which is a maze of tubes in the head and this allows them to take air if the water they are in becomes stagnant. This is true for wild bettas which have adapted to living in bodies of water that other fish will die in. For instance in the wild where the floods happen, the water recedes leaving fish stranded and the Bettas survive because of this special adaptation.

Found this for you to read.
http://www.aquariumpharm.com/bettas/allaboutbettas.html

thanks alot thats everything i wanted to ask right there on that page!

I agree with Sandy I wouldn't put a betta in less then 4 gallons. Think of it this way just because human's can live in closets dosen't mean they do it's the same way with Bettas and those tiny 0-2 gallon tanks (or cups)

i keep mine in 20 litre tanks - 5.3 US gallons - probably 5 gallons cause i dont fill the tank to the top etc - that way there is condensation on the glass lid - creates a humid environment or some such - they seem to love it.

I get very dispondent when I see them in cups and tiny bowls in stores - poor fish dont move cause they have nowhere to go - and trust me - they are an active fish