Most aquarium plants do not thrive without CO2 fertilization - but algae does! So without extra CO2, your new plants can suffer and algae will take over your tank. A simple and inexpensive way to supply extra CO2 to the plants in your aquarium Easy to install, use and maintain Suitable for starter-sets, where even small amounts of extra CO2 will make a positive difference for the plants How to use the product The table shows recommended daily dose (ml) in aquariums of different sizes. The chamber should be vented once a week by removing the silicone stopper. 1 CO2 cylinder contains approximately 5000 ml and will last for 1 month in a 60 L tank (see the table).