Ditto on moving up to about 3 gallons.
I had my betta in a 3 with a whisper filter and a so so light, in a bright room. With an ozelot sword and floating brazilian pennywort. It was ok but even with weekly 50% water changes I fought nitrates.
Then the filter broke and I followed some advice that it might be OK without a filter. Sure enough, the plants started growing like crazy and now I have zero ammonia, zero nitrates. I think the plants suck up ammonia before it converts to nitrite or nitrate? The ozelot sword looks fun and funky since it's big, it's like the fishy equivalent of a person beside a giant oak tree. The floor is clean and bare and the pennywort goes mad and looks pretty on top.
Pennywort looks stringy and weedy from the store ... I cut it in small pieces below each branch so it's a bunch of v shapes ... I hook some around the heater cord then hook it around itself, searching them together. Then they get pretty.
Yes maybe this week I'll deal with my inability to upload photos so I can share better ...
Sent from my iPhone with three hands tied behind my back.