An external in-line mixing valve that will adapt to any Clack 1″ or 1.25″ control valve, 1191 and 1190FP in/out head or inline bypass and will allow blending of raw water back into the system.
You can use the external in-line mixing valve on water softeners to blend a desired amount of hardness back in the line or use it on a carbon filter to blend a small amount of chlorine back in the line.
