While the yields are still good with CO2 enrichment and no air exchange in a sealed environment, the hybrid CO2 enrichment with air exchange works better. You get bigger nugs and more weight. I don't know the exact science of why this occurs but I can tell you from experience of doing it both ways and my best results have been using both CO2 enrichment and air exchanges. My og kush plants thrive this way. For example when I ran CO2 in an enclosed room that uses a scrubber to clean the recycled air, I would average around 2.3-2.5 pounds per gavita fixtures. The nugs do get dense but not very big compared to the hybrid system. When I enriched with CO2 with air exchange I started hitting 3+ pounds per gavita fixture. My og kush nugs were bigger and did not rippen so quick. All my buddies that are getting over 3 a light are doing the same. The completely sealed grow room environment enriched with CO2 with no air exchange is an inferior technique to the hybrid system. 1st photo is the the top bud of my og strain using the hybrid system. The second photo is a top nug with no air exchange running CO2 in a sealed environment where the air is recycled and only scrubbed.
Old post but was interested in when the air exchange happened? was it temperature based? or just based on a schedule? Looking into a hybrid combo. Thanks in advance