Plants use CO2 in photosynthesis. Without CO2 photosynthesis effectively ceases. By increasing the atmospheric levels of CO2 it is possible to increase the rate of photosynthesis. This means cell division (growth) occurs more rapidly; which means plant growth occurs more rapidly. CO2 can increase yields by 10 – 30% and reduce growing times by 10 – 30%. See A Guide to Co2 in the Grow Room to learn more.