The TNB CO2 Refill gives growers the ability to reuse their existing Enhancer bottle while saving money and reducing their environmental footprint at the same time. Simply empty the contents of the original bottle and give the bottle a quick rinse. The contents of the Refill Pack can be added and instantly CO2 is once again available for use. Boosting plant production and improving overall health, CO2 is an essential element of photosynthesis and often one of the most overlooked components of plant growth. The TNB CO2 Refill consists of the same great recipe while combining convenience and an amazing option for those looking for passive CO2. Research has shown that plants can use up to five times the CO2 that naturally occurs in the air. With The Enhancer known for delivering levels of CO2 only comparable to a propane or natural gas burner, there is no question many growers will be turning in their tanks and introducing CO2 with this safer and all natural method.