co2 tanks

Well my last grow i used a 20lb co2 tank ehich was $20 to fill in my 5x 10 closet. Whats the best way to introduce co2 in a closet this size.

the BEST way is with a monitor and regulator. A bit pricey, but you can regulate the perfect amount. Some people hook a regulator into a timer. Good for bursts of c02, but in order for you to really benefit from it's use, you need to maintain a steady level during lights on period.

the best and most efficient is a co2 generator and controller. you can get started for around $500. my 30# propane tank cost $23 to fill and lasts 3 months. i was always concerned with heat and got the minigen that can be water cooled, but havenever used the water cooling. it puys outvery little heat.

In a small area where the gardener does not plan on expansion, CO2 bags like Exhale (there are a few other brands out there) can be more cost effective. About $200 worth in a 5x10x8' would get you in the 1200-1300ppm range for six months straight. For larger rooms compressed gas and a controller is the is the only way to go. Burners are good in colder, drier environments.