View Full Version : I need flow switch recommendation

10-27-2009, 03:37 AM
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.

10-27-2009, 04:11 PM
Liquid chlorine (bleach) is really cheap. Why not just take off your outside faucets before the retention tank, but after the injection point, and use chlorinated water for the outside faucets?

10-28-2009, 01:35 AM
Thanks for the reply Bob999.
Having chlorinated water on my outside spigot would work sometimes. A lot of my outside use is for watering plants. I would think that would be hard on the plants.
I could just unplug the thing each time I need to, but my memory is bad. I have a long history of forgetting things like this!
If I can not find a flow switch, I might wire a lighted switch located where I can't miss turning it back on.
Hopefully I can find a flow switch for a hot tub, pool filter,... that will work.

10-28-2009, 05:58 AM
Unless you are chlorinating a high levels I don't think it is an issue with plants. Remember that all municipal water supplies are chlorinated and people in cities use their city water to water plants, lawns, trees, etc.

I am assuming that you are chlorinating because of a problem--probably bacteria or iron--and that it is important that all your domestic water be treated by chlorination. If that is the case you run the risk of failing to chlorinate some of your domestic water when you shut off the chlorine injection for outside use. If you then try to design a work around for that problem you will either end up with significant inconvenience for the family while you are watering outside or you will have to install a fairly sophisticated and expensive control system to properly chlorinate the domestic water while you are watering.

10-28-2009, 09:46 AM
You could hook up a timer with a relay to shut off the injection pump. That way, after the set time it would automatically revert to 'normal' and start adding the chlorine into the system. Timers are readily available with either settable or fixed intervals. The relay would be NC, and set to open while the timer was on. Many also have a cancel function if it was set longer than you needed, or to override for some situation.

10-29-2009, 01:52 AM
You guys have given me something to think about.
Both suggestions are good and valid.

Thanks a lot for your help!