to set up a typical feed back loop to control the automated flow control valves 28 32 on both the wac tank feed passage 30 and the bypass around the wac tank via passage 26 b a control circuit forming part of a controller 44 would adjust the flow through the wac tank 10 and the bypass 26 b around the wac tank to achieve the desired ph range a typical proportional integral derivative pid control would be built in to the circuit design to minimize u201c hunting u201d or oscillating caused by rapid valve movement and the associated downstream ph result pressure sensors 46 48 would be included in the feed water supply and down steam of the wac tank to control the degree of opening in both the flow control valves 28 32 as a pressure drop is sensed by the feedback from both the sensors the control 44 would open both the valves 28 32 while keeping the same ratio of split stream the ph control would coordinate with the pressure control to produce a mixed stream within the desired ph range while still maintaining an acceptable pressure for the mixed streams intended use for instance since the wac system is being applied to the hot water feed in a home the available water pressure in a shower is an important issue as it not only might determine the flow in the shower it could also affect the hot to cold water ratio blend which could cause problems in the shower those skilled in automated controls can envision numerous ways that this can be carried out using both off the shelf plc controls or custom designed circuits.