Pro Leaf CO2 RegulatorThe Easiest and Most Effective Way to Add Extra CO2 to Your Grow Room The Pro Leaf CO2 Regulator is designed to fit onto a CO2 gas cylinder, utilizing a solenoid valve to release the gas as needed. It operates according to settings on the Pro Leaf CO2 Controller, ensuring ideal CO2 levels are maintained in the grow room at all times. This setup promotes faster and larger plant growth, optimizing your harvest. How the Pro Leaf CO2 Regulator Works CO2