Co2 is a very important element in plants growth it is a must have, if exceeding whats naturals found in air (390ppm)will only benifit if all other conditions are ideal with co2 enrichment plant enjoy a higher temp of mid 80s to low 90s, but becaus you have noway of regulating or monitoring your concentration, I will not recommend you raising temps, co2 will not be benifical if your ph is off or if you are not feeding with proper ppm with your high quility nutes. co2 enrichment is vey benifical but if you have one problem co2 will not help. So needless to say you have to have a problem less grow. Hope this helps
ps. Co2 does help growth it helps all growth from stem to bud it allows the plant to speed up photosynthesis with increases rate of growth by up to 40%