Ideal for beginners and low light tanks, with low CO2 demands, these sets are the perfect co2 supply for small planted aquariums. The Ista Disposable CO2 Can is easily adapted for any kind of aquarium you have. If setup correctly, you could have CO2 supply for several months. For low light tanks, the rate of 1 bubble every 5 seconds usage for months. Place the CO2 diffuser to the very bottom of the tank to achieve the best co2 diffusing effect. Perfect co2 supply for small planted aquarium or beginners. Extendable CO2 diffusing chamber provides options of CO2 supplying rate. Simple to set up and operate. Included: 1 CO2 tank, 1 check valve, 1 CO2 diffuser, 1 flexible tube.