Carbon Dioxide (CO2) is one of the easiest ways to accelerate plant growth, producing up to 40% more flowers or fruit. A propane or natural gas CO2 generator is the most cost effective way to add CO2 to your environment. Many greenhouses use CO2 generators to boost CO2 levels safely and economically. C.A.P. has developed some of the safest and most reliable CO2 Generators; capable of producing between 3 and 26 cubic feet of CO2 per hour.