Wow. Just an update, I finally found a small heater suitable for the tiny tank I have. I had thought that I would have to buy a full-size heater and then figure out how to use it and constantly adjust it...well turns out that heaters are a lot more user friendly these days. Tetra makes a short little heater with a preset thermostat that keeps the water at a constant 78F(~26C). Works great and my male betta seems really pleased with it! He's more active than he was before and I've even caught him "lounging" in the warmest waters immediately above the heater. I think he likes it
Can't wait to see how the plants react!