Get the basics down first as TomatoPie says. Over/underwatering are the #1 mistake growers make and co2 is only useful when the plant is healthy and well cared for. co2 will make things happen faster....so a small mistake is a BIG deal. If you have enough air flow through your intake/exhaust you will be fine. I would recommend a burner if you can manage the heat. Mine runs about 15sec at a time with the off period dependant on RH%. If not venting it is several minutes. Stays between 1100-1500 ppm and the base level before was 700 ppm. Used in flower only with exhaust ducted to veg. Nute uptake is much higher with co2. Adding co2 should be your last priority until you know what you're doing.....but after that it's a GREAT investment.

http://forums.cannabisculture.com/forums...rue#Post1677629