210 ppm?? Co2 is 350 or so ppm and it's only 1/3 of 1% of our environment. You mean 210.000 ppm. Or 21%. You can get a O2 sensor control unit at science supply stores. 23% O2 will increase growth and vigor. With higher O2 you can go a little higher on co2. You need to purge the room twice a day. At lights on and lights off. A dehumidifier twice as big as before. If your old one was on more then off, three times. Clean filter weekly. I don't know about your exact setup, but,,,, I do know sealed room and O2 enrichment..
After purging at lights out to lower co2 don't stop O2. Keep O2 at 23%. Weed uses O2 in the dark. The more root growth at night, the more the plant has to catch up to. And they do catch up. Once you get good at 23, go to 25%. Increase co2 again. Different strains respond differently. Some you can push this far and others will stumble. Watch and adjust. With more growth you need to water more. Which is why more dehumidifiers. Also the mass moisture on the ground. Might want to put watering lines deep so surface of soil isn't increasing moisture in room.