I have a very elaborate well water treatment system that had been plagued with problems. One problem is I am using chlorine to kill bacteria and then removing the chlorine with charcoal before the water gets to my RO membrane. Anyway that is more than enough background.
I decided to eliminate the chlorine and install a whole house UV filter. The UV bulbs are good for 9000 hours and most people, I assume, just plug them in and leave them. I fail to see any benefit to the light being on when there is no water movement so I figured I would control the light with a flow switch. All of the flow meters that I found on ebay, Amazon or Grainger were either too expensive or did not give me the specifications that I was looking for. So its do-it-yourself time.
The object of this project is to detect the movement of water in a 1" PVC pipe and turn a receptacle on and off.
This is the finished project. Most of the PVC was just stuff found in the workshop so please ignore the stains.