Check the listing for details. CO2 Generator System DIY Accessories Kit With Diffuser For Aquarium Live Plants. Condition: New. Listed at 24.52 USD. Description: Well suitable for DIY Co2 system and low cost planted tank use. Getting Basic, Easy set up, Simply, Nano, Cool, Low Price, Good Looking! Condition: new Package included: 2x caps, 1xFine-tuning valve, 1xswitch valve 1x Pressure gauge 1x Acid suction tube (including water suction ball) 1x Acid transfer pipe (including tee) 1x Magnet CO2 tubing(1.6m) What you need to prepare this system?? 2x 2 Litre of Coka Cola plastic bottle 1x 200g of Citric acid or 200ml of vinegar 1x 200g of baking soda Note: 1: The bottle must be carbonated beverage bottle, do not use the bottles which supply green tea, mineral water.etc 2: Trimming valve regulation avoid by sudden big or small, can’t suddenly turn up, after immediately shut down again, so as not to cause abnormal pressure to the bottle.