For smaller aquariums and beginners, a bio CO2 system is a very compelling solution as an entrance to the world of carbonating an aquarium. AQUARIO offers some interesting solutions for bio CO2. The neo Bio CO2 consists of an acrylic diffusor with a suction cup, a fitting CO2 hose and a plastic incubator filled with a gel-like nutrient solution. Just add water and yeast (included) and the production of CO2 starts within 1-2 days due to fermentation. The diffusor distributes the fine mikrobubbles of CO2through the aquarium which have an optimal contact time in the water column due to the small size of the bubbles. Depending on the ambient temperature, the bottle contents can produce carbon dioxide for 20 to 50 days. As the pressure decreases, the nutrient solution should be reactivated. To do this, remove the remaining water and mix a new culture medium with the gel remaining in the bottle, fresh water and new yeast. Another yeast portion is already included in the delivery. In addition, refill sets are available here in the online shop with the neo CO2 refill, which contain fresh gel as well as the yeast bacteria.