The Johnson Natural Gas CO2 Generator Classic is built for growers who want serious CO2 output with minimal fuss. Designed to enhance photosynthesis and plant growth in medium to large grow spaces, it runs on clean-burning natural gas and delivers a steady flow of CO2 that keeps your plants thriving. Made with simple controls and compatible with standard environmental controllers, it’s easy to dial in the perfect CO2 levels for the unique needs of your grow. Its rugged metal housing, corrosion-resistant components, and built-in safety features like automatic shut-off make operation stress-free. If you need something smaller, check out the Small Stainless Steel Natural Gas CO2 Generator 4.2 from Johnson. Growers looking for a flexible dual-fuel option, will find the LP/NG-10 CO2 Generator from ProLeaf runs on both propane and natural gas and includes digital controls for precise regulation.