Aquatic plants greatly benefit from CO2 injection. The more plants you have, the more CO2 is needed as a carbon source. The DOOA CO2 System Kit is a premium quality CO2 injection starter set consisted with CO2 FOREST BOTTLE. CO2 SYSTEM KIT includes necessary equipments such as CO2 COUNT DIFFUSER, a CO2 diffuser combined with CO2 counter, BALL VALVE and CO2METAL STAND. It is perfect for small aquarium, such as DOOA System Terra 30/Aqua 30 or under 60cm width planted aquarium.