Active Air-Timer Options:Hydrofarm CO2 (1-20 cu ft per hour) with Timer Slip over hose end using

Slip over hose end using a pushing and twisting motion

• Comfort Grip™ improves control and reduces hand fatigue

This high quality 55-gallon drum is black in color and comes with a pre-drilled solid cover and bolt ring closure

Take the "Natural Path" in encouraging the production of blooms

• Loaded with B-vitamins

Active Air-Timer Options:Hydrofarm CO2 (1-20 cu ft per hour) with Timer Slip over hose end usingDeliver 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.