Fluval Pressurized 95 g CO2 Kit - For aquariums up to 190 L
The system is easy to set up. Once in place all you need to do is open the valve on the pressure gauge and count the bubbles. I find it easier to open more than I need then start to close it until I get the right amount of bubbles. I have given 4 stars because when I close the valve at night by morning water has travelled back up the tubes and I can't work out why. Pressure is leaking somewhere and as of now I haven't found where. Not sure how long the gas will last but so far the gauge hasn't moved.