Just add citric acid, baking soda and water to the bottle, which can produce carbon dioxide. The plant’s metabolic rate can be increased rapidly, creating the best growing conditions for fish. It is the best choice for making CO2 equipment at home. It’s easy, safe and economical. Features: Be made of stainless steel. It is strong, durable and effective. Plugs and pipes well sealed, tight, not deformed, never loose. Professional pressure gauge to monitor pressure. Cheap, simple to create pure CO2 permanently by chemical reactions. Bubble counter with non-return valve: indicator of CO2 flow and prevents water from flowing back into the bottle. Equipped with a safety valve, the pressure is greater than 4 kg, the pressure will be automatically reduced, the pressure of soft drink bottles is 8 kg, safety is ensured. The safety valve supports manual pressure relief. When the pressure is less than 4 kg, it can be released manually by pulling the ring of the safety valve. It’s very safe. Any