Hydro-Force is designed for use with incoming water pressure of 400 P.S.I. The water flow is automatically reduced as it passes through the injector valve, thus reducing the pressure approximately 64%. To obtain the actual working pressure of your Hydro-Force Injection Sprayer, multiply your incoming pressure by 36%. The Hydro-Force injection sprayer is factory set inject chemicals at a 1 to 8 ratio. Other chemicals may be used but should be prepared for a 1 to 8 dilution. The Hydro-Force pressure can be increased by putting a smaller jet at the end of the wand. This will, however, decrease the injection rate of your concentrate chemical. Your injection ratio may also change depending on the viscosity (thickness) of your concentrate chemical. The 1 to 8 ratio is based upon chemicals with a smilar viscosity to water. The injection ratio can also be slightly affected by your main flow water temperature. This is generally not enough of a change to appreciably change effective-ness of your system. We do, however, recommend the water temperature be kept below 200 degrees Fahreheit, as higher temperatures can cause problems on the injection.