Thank you for the replies! I still have the carbon balls in, but I think I'm going to switch them out for purigen. Just have to figure out where to get the bags for it.
I decided to see what my tank could handle after a couple days up and running, so I dosed 8 drops of Dr. Tim's ammonia solution. The first 5 or so days the ammonia was around 2ppm (I have trouble comparing to the API color chart, though). I still cant tell exactly where its at, but it seems to be between 0.5 and 1ppm now. The nitrite is around 0.5ppm and the nitrate about 5ppm.
I'm wondering what my next step should be. I accidentally had the heat cranked to 84 degrees because, as you correctly guessed, the heater was too much. I'm re-calibrating it now to see if I can get this heater (Elheim jaeger) to stay at 78 degrees.
I'm wondering what I should do when the ammonia gets closer to 0ppm. I have aquarium co-op easy green liquid fertilizer, and I'd like to start dosing that because my plants are browning a little. I'd probably have to do a water change before that, correct?
All I want to put in there is a betta, and given that a surprise snail is thriving in the tank, and some green algae is forming on the stone (along with some white fungus on the spiderwood), I feel like I'm not far off. Am I correct?
Thanks again! P.S. I got rid of the sword - it was dying rapidly anyway.