I'm am not a pro on beta fish but I had one in a large glass 2 1/2 gal. cylinder container 2'x10" with lights and a plant with plant roots only in the water . The plant sat at the top of the container a kind of micro climate with fish, plant, water. There were glass marbles about 3" on the bottom with a bottom layer of fine charcoal to help control fish waste. I used distilled water because our well water was to harsh. Beta fish are air suckers so they don't require a lot of oxygen to be pumped in the water. The fish lasted for almost 2 years.
