Active Air CO2 System with Timer, 0.2-2 cu ft per hour

Deliver growth-boosting CO2 with our user-friendly, easy to operate system. With its programmable timer, it will automatically maintain ideal CO2 levels for optimum growth. For small to medium size areas, select the COSYS; for larger than 10' x 10' areas, select the COSYS20. To use Hydrofarm's CO2 Flow Rate Calculator, click HERE NOTE: Current COSYS & COSYS20 now come equipped with a black rubber O-ring that has replaced the white plastic washer.