I have an old homebrewing co2 canister, but I don't think that the regulator will allow the pressure to get low enough.
Lights, I have a CF 65w, and a CF 75w on it for about 12 hours each day. I am not dosing anything right now, but I am headed to the store today to grab ferts, so that's done. Water is pretty good though. I do use the cheap tests once a week, and change a couple of gallons out each week, so those params are good. Just want to get that PH down. Overall the tank is healthy, but I think it's currently not THRIVING. That's my aim.