Is it possible to add co2 to your outdoor grow?

Say by creating a transparent box to hold it in?
i read that you should only add c02 when the lights are on (indoor). . .my plants are no bigger then 4 feet so it wouldn't be hard to make somethin to go over them.
i just bought a paintball gun and was wonderin if i rigged it to let out 5 or ten ounces durin the day would i see an increase in bud size now that we are gettin late in the summer. and if this would work how many times would this be possible to do before harvest time (etc. once a week ,twice, everyday?)
thanks for the help!
s0st0n3d Reviewed by s0st0n3d on . Co2 Question Is it possible to add co2 to your outdoor grow? Say by creating a transparent box to hold it in? i read that you should only add c02 when the lights are on (indoor). . .my plants are no bigger then 4 feet so it wouldn't be hard to make somethin to go over them. i just bought a paintball gun and was wonderin if i rigged it to let out 5 or ten ounces durin the day would i see an increase in bud size now that we are gettin late in the summer. and if this would work how many times would this Rating: 5