CO2 Question.......

I started using my co2 tank again after having my room controller fixed, One thing I noticed Is I can go in and out of the room without the co2 going off to much, however, If I place a half doz plants in the room the co2 goes off and on for 20 min........ do the plants use this co2 this fast then get saturated ? or is it just coincidental...........

not sure i know u breath out co2 and take in oxygen and your plants take in co2 and make oxygen so it would make sense that it would come on less with you in there then with the plants but honestly i dont know for sure sorry couldnt help more