Jef79answered grow question 4 years ago Hello.. Hope you are well.. Co2 in a small room isnt needed necessary.. But.. If ur room gets very wsrm it will help ur plants breathe easier.. Its the same as putting a human on a running machine in the sun, give us more oxygen and we can preform better.. Same principle with ur girls.. U mite not "see" any difference but in the long term ur girls will benefit.. If u think it wil get sucked out of ur outtake fans then place in a position under her canopy to let it pull thru n past her leaves.. Stay safe n gud luck.. 👍🍀