The great co2 debate.
My op.
Co2 is heavier than air. Also heat rises co2 is cooler than tent air. (Assuming tent)
So most of us vent and pull air from the top. So introducing it there to let it sink, well IMO bad idea. Just sucking it right out.
Introducing to the bottom. My theory is. It will disperse pretty quick. But with fans pulling up and co2 wanting to sink as much as it can before being pulled up and out. I do think you could essentially create your co2 atmosphere in the "prime" zone with the vacuume affect and the gas wanting to sink. Making your densest area of co2 right in your plants.
Plus it will be pulled up and through plants out of the exhaust.
Just my stoned notion