I'm a 50galkid, but i also know about small aquariums that would "Light" up your bettas mood.
In these post's I will be sharing perfect tanks for bettas and reccomended "doo-ha's"
Everyone knows bettas are usually kept in unfiltered bowls or cups with limmited room and oxygen.
You can use a 10gal and a divider but thats half of the aqaurium for only ONE fish.
These are some tanks that may be small but at least should "Shine" your bettas mood.
Tetra 1.8gal water fall globe,
This is why I said "Light" and "Shine" because this tank has what my bettas love: Light to shine, Room and it sometimes reflect my betta making him to "pop" his tail and fins out. This aquarium has a low voltage AC cord so if it gets wet it won't to major damage. It has abot 7-8 Led lights that bring out my bettas coulor. The "Water fall" is actually a filter with a long drop so it makes a "waterfall" type noise.
Bettas don't need light all the time so they sometimes get stressed in the water, therefore there is a easy button that shuts of the light but keeps the filter on (To turn off the filter unplug the Ac cord)
There is enough room even for at leat 2 neon tetras for your betta. (Search it up neons CAN go with bettas, not saying they WILL because they may not get along) The addision to the filter is most people would think "hey if it over flows wont water be every where?" The answer is NO theres grooves (Slumps) that block water that over flows and pushes it back into the tank.
My recommended "do-ha's" are the tetra mini heater it will fit well in the tank and will make the water more suitible for the betta
P.S its a bowl
< Really who knew? (derp)