Carbon Dioxide is one of the most important factors in an indoor growroom or glass house. Photosynthesis is the term used to describe the process by which plants combine Co2 molecules with water molecules to form complex sugars, there is a resultant spare oxygen atom which is released back into the air, the sugars being further processed by the plant to form natural polymers for growth. The ambient level of Co2 in air is 300-400ppm, fast growing plants in your grow room or glasshouse can use all the available Co2 in less than an hour slowing photosynthesis and therefore growth to a virtual halt. Evolution Digital Carbon Dioxide Controller This Controller is the most advanced of it’s kind and has more features and functionality than any other product on the market. It can be used either with or with ought the Evolution Carbon Dioxide Sensor and can be interfaced to an external thermo / hygro stat providing a cheap entry level system with an easy & affordable upgrade path in the future.