you need to concentrate on the basics of growing weed and not on ghetto co2 jugs...It has to be above 85(88 ideal) degrees for co2 to be effective.
the biggest factor here, has not even been mentioned.

What type of system/grow are you doing? It was nice of britewire to look things up for you, but with your inexperience, you are asking the wrong question's.

If you know you are growing with cfl's...just say so...then folks around here can help you. But, I think you are putting the cart before the horse.

Make a solid plan before you germ those good genetics and waste them.

you DO NOT need co2 until you have harvested a decent yielding plant and have developed a clue as to what you are doing. Hope you take this to heart, lw