2 months ago I installed a chlorine injection system with a 120 gal retention tank. I also have misc. other equipment to treat my water.

I thought I could wire in a flow switch that disconnects the chem pump when the outside spigot is flowing. This way I will not inject chlorine into retention tank when my bypassed outside spigot is flowing. With extended outside spigot use, it could really put a lot of chlorine into tank!

I am an electronic technician, I know theoretically how I could hook this up. But I do not know what would be the proper type switch for this application, or where I could find one.

Up untill this morning everything worked fine. I unplugged the injection pump while power washing my house yesterday. My wife plugged it back in for me.
She plugged it into the "always hot" plug I use for priming, instead of the "switched with well pump" outlet.

So the injection solution tank emptied. Hopefully the pump (chem tech) is still okay, along with other things that could have happened from overchlorination.

I have been thinking of doing this before, now I see a real need for this!

I have gotten great advice here before, thanks in advance for your help on this one.