The CO2 supply should be 99% and not have siphon tubes. CO2 pressure should be regulated to 15-20 psi. CO2 tank regulators can be purchased through Caron customer service. Once the cylinder regulator is installed, connect the outlet of the regulator to the hose barb fitting using the tubing and clamps provided. An inline HEPA filter is provided to remove any contaminants in the CO2 gas supply. Check the connections closely for leaks.