For the cycle — if you're already logging params for reef, just add the betta tank to whatever you use. I still write mine down in Reefly so I'm not guessing if nitrite spikes day 4.
Once he's in, leave the decor alone for a few days. They sulk when everything's new.
Get the heater. Bettas aren't tropical reef temps but they want stable low 70s to high 70s. Swings mess them up more than being slightly warm or slightly cool.
Plants help if you want an excuse to buy more stuff. Anubias and java fern are hard to kill. Skip sharp gravel — their fins tear easy.
