Try this neat idea
There is a product on the market called a Water Witch. It is a solid state bilge pump switch. There are also a few others which work on the same principal. Basically when the electrodes have water between them, the conductivity of the water closes an output relay. So here's the arrangement: Take a small impeller type pump with let's say 3/4" inlet size. On the inlet, plumb a short length of PVC hose tubing. Then join in a 2" length of copper pipe with hose clamps. Then another length of plastic hose about 4" long. Then another 2" copper tube, and finally another PVC tubing to your drain. The impeller pump and tubing has to sit below the level of your shower drain. Take the 2 electrodes from the bilge pump sensor, and connect them to each of the short exposed sections of the copper pipes. Now when you use the shower, just enough water will back up in the tubing to automatically start the impeller pump. As soon as the water is gone, the pump stops. You will need to put a one way valve on the output of the pump to prevent cycling from backflow. What do you think? Art Boas
