wonderful grow! plants love the conditions you've created for them! CO2 is best used and noticed while plants are in flower. CO2...if you have powerful lights, and you have, the plant can absorb only as much light spectrum, the CO2 opens them to be able to retain more light/energy thus leading to bigger yields. Also have in mind the density of CO2 vs the rest of the air in the tent, the air currents and extractor fan if you have one. They need to be tuned not to counteract each other
like