DIY CO2 Kit — 1-Bottle Yeast System

The DIY yeast CO2 kit is the most affordable way to begin injecting CO2 into a planted aquarium, requiring no pressurised cylinder or regulator. This single-bottle kit provides all the components needed to generate CO2 from a standard 1–2 litre plastic bottle using a mixture of water, sugar, and yeast. The pressure bottle cap seals the bottle and routes CO2 through the included check valve, airline tubing, and ceramic diffuser. While output is less consistent than pressurised systems — typically varying with ambient temperature and the age of the yeast mixture — DIY CO2 can meaningfully accelerate plant growth in small tanks at a fraction of the cost. Ideal for planted aquariums up to approximately 60 litres.