Active Air-Timer nutrient-combo They feature a convenient access

They feature a convenient access porthole (porthole cover available separately) and multidrill access points to install various meters and pump cords

Low maintenance and oil free

Make Defguard part of your all-natural protection plan

It's a great resource for customizing your feeding schedule

Active Air-Timer nutrient-combo They feature a convenient accessDeliver 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.