LOL, trust me, if this is your first grow, you will be in and out a LOT... which in turn (as long as you don't hold your breath) will supply plenty of Co2 for the plants (given you do not have a lot of plants). I went with a DIY c02 generator that has worked well for me.. or it just might be that I have been in and out over a thousand times LOL. either way it would not hurt if you have the time and materials. A pic of mine below.