i think C02 can help, but like said its tricky and probably expensive to get right...

for the average grower, i think money and effort is probably better spent on other aspects, like nute ratios, soil mix etc.
with good ventilation, theres 'enough' c02 in the air, adding c02 is benificial up to a point, but IMO not worth the efort unless the other more controlable variables are tweaked to max potential
babystarbud Reviewed by babystarbud on . Seriously - Discussion On Spraying CO2, Any Point? . Seems to me the amounts of CO2 transported to the plants from spraying seltzer water would probably be quite small and sporadic. And do the leaves absorb CO2 in that manner? Another problem is that preferably when applying CO2 you want maximum lights going and even quite high heat, risking burns. Is it worth the effort?' . Rating: 5