Dennerle CO2 Set Carbo Bio Start 80 is a bio CO2 fertilisation system for freshwater aquariums. The Carbo Bio Start 80 bio CO2 fertiliser system supplies all freshwater aquariums up to approx. 80 litres with vital CO2. It is ready for operation in just a few steps. CO2 production starts after 24 to 48 hours. A pressure-resistant CO2 hose and a Dennerle Micro Flipper ensure fast, effective dissolution of the valuable CO2 in the aquarium water.Dennerle BIO CO2 exploits the well-known fact that yeast cells are able to produce CO2 from sugar in the absence of oxygen. A problematic aspect is the fact that a fermentation process with pure sugar normally begins at a very fast pace, only to drop away substantially after just a few days. As a result, the aquarium receives too much CO2 at the beginning, and too little shortly after. In contrast, Dennerle BIO CO2 with CO2 control gel produces a virtually constant level of CO2 continuously for over 30 days, that is, for more than a month! Each CO2