This is one of the biggest advantages of the 640g system! A standard 640g N2O cylinder contains significantly more gas than the small 8g or 60g cartridges used in other makers. On average, you can expect to carbonate between 90 to 120 liters of water with a single cylinder. The exact number depends on your preferred level of fizz (more carbonation per bottle uses more gas) and the size of the bottles you are filling. For a household that enjoys sparkling water daily, one cylinder can last for many months, making it very economical and environmentally friendly with less waste.