Just add citric acid, baking soda, water into the bottle, can produce carbon dioxide. The plant metabolic rate can be increased quickly, create the best growing conditions for fishes. It is the best choice of making CO2 equipment at home. Features: Professional CO2 generator system with stainless steel bottle, better than simple plastic bottle generators. It is more reliable, steady, durable and efficient. Safety valve will open automatically when the pressure over the safe pressure. Bubble counter with check valve: Flow-rate of CO2 gas indication device and prevent water flow back into the regulator. Large amount of CO2 may cause fish dead. It is recommended to reduce the CO2 volume at the beginning, 1 or 2 bubbles per second. One time's reaction can last for 3 to 4 weeks using. Any problem, please contact our store without hesitation. Honor to serve you! Specification: Name: CO2 generator system Main material: Stainless steel Main color: Silver 3 size optional: 1L: Height: 29.5cm; diameter: 8.6cm; thickness: 0.12cm; 2L: Height: 47cm; diameter: 10cm; thickness: 0.12cm; 2L double: 47cm; diameter: 10cm; thickness: 0.15cm; Raw material ratio 1L: Citric acid 100g+baking soda 100+water 150g 2L: Citric acid 200g+baking soda 200+water 300g 2L double: Citric acid 400g+baking soda 400+water 600g Note: Excessive or double addition of raw materials and water is prohibited. Invert the bottle and disassembly are prohibited. Package Information: Package size: 15 * 15 * 44cm Package weight: 1L: 1340g; 2L:1840g;2L double: 2429g Gift Box Packaging Package List: 1* Stainless steel bottle 1* Pressure reducing valve 1* Bubble counter with check valve 1* Pressure gauge 1* Built-in safety valve 1* Fine adjusting valve 1* ABS multiple filter 1* 1.5m tube 2* Suction cup 1* Manual