I am thinking of installing an Apex ph controlled CO2 scrubber. CO2 levels in my "tight" house are around 1300 ppm versus 500 outdoors. For logistics reasons can't run current skimmer air intake outdoors. pH in tank 7.8 with Alk= 8.0 Has anyone had experience with a solenoid controlled air intake where valve would open to scrubber say with a ph less than 8.3 and draw room air for ph over 8.3? Can you give some details as to setting it up? Solenoid part number? ( I have looked at the Carr McMaster catalog and find it overwhelming- their customer service won't advise on specific applications!). Any help greatly appreciated.