Betta In A Half Gallon

[Gregoriousgouramiguru]

I have a blue betta in a nice little half gallon with a plant,is that too small?

 

[OldMan47]

The half gallon does not give him much swimming room and will require a great deal of attention to keep it clean. As long as you are not trying to find a place for 50 at a time, each one having at least 2 or 3 gallons is usually the accepted minimum. By having a little more space in the tank, there is room for the needed heater, a little cover from an artificial plant and a small filter to help keep the water clean. Be aware when selecting a filter that bettas in general do not like high flow rates. That does not mean, as some seem to interpret it, that they don't like any circulation. They just need to be protected from strong water currents. I keep mine in much larger containers with other small tropicals so they see normal filter flows and have lots of room to swim around. They even play in the filter flows once they get used to it although at first they seem reluctant to get near the higher flow. My guess is that they have been reared in such small containers with no flow in them that they have not developed the muscle tone needed for more vigorous swimming.

 

[Miss Dib Dabs]

^Absolutely true. I bought a lovely male CTPK last year who was obviously unused to space and had his fins nipped in places. He now lives in a 7g tank, well planted and has grown huge by standard betta sizes. His muscle tone changed his body shape into a more robust, strong looking fishy and he's already had one spawn this year that lived with him for about 6 weeks.
You are definitely best off giving your betta more room to play in. They seem far happier with a little more space and some really do enjoy the filter flows.
P.

 

[Amunet]

I think the previous 2 posters have pretty much said it all.
A gallon should be the minimum to keep a betta in, and even then, it should only be temporary imo.