2) is a colorless, odorless gas that occurs naturally in our environment. It is normally present in the atmosphere at a2 we would probably2 makes our2 levels because of more efficient photosynthesis and a reduction in water loss. There2 molecules with water molecules to form complex2 in air is 300-400 PPM, fast growing plants in your growroom or glasshouse can use2 in less than an hour slowing photosynthesis and therefore growth to a virtual halt.2 level in your growroom causes more sugars to be produced allowing the plant to grow bigger and faster. The optimum level2 for plant growth is generally accepted at 1200-1600 PPM, plants grown in this environment can grow up to 40% faster thus