Disclosed herein is an automatic gain control circuit including a power detector. When the switching member is swung to the OFF side, the stopper is engaged with the output gear at the same time as the switching member is disengaged from the triggering member or before the switching member is disengaged from the triggering member. Except for the pretreatment sections, each of the treatment sections are contained within an enclosure cabinet that includes controller and control panels as well and feed containers for the conductivity fluid and polymer. The interface translates the industry standard Ethernet, TCPIP and HTTP protocols used on the Internet into data recognizable to the PLC.