[Sasha_V]

After six failures of various commercial units, I built my own. Then I built two more for friends. The oildest is now more than 3 years old and still working fine. PVC vertical tube. Internal connical foam float with small weight on the bottom to act as return and a magnetic switch (no contact neccassary, and no metal exposed to water). The float rises a couple of inches and the mag field activates a relay (the weak point as I see it, but one completely in the dry of the breaker box). Relay activates the pump.

I had an idea about adding a small mast to the float with a second mag-spot and a second mag sensorfurther up the tube. Float rises slightly, bottom pump comes on, float rises more, both secondary and primary pump activates as both mag sensors line up...Have not tried that one yet.

The nice thing about the mag switch is that there is nothing to corrode or leak away or for the pivot point to clog or corode...and all the other things that go wrong with standard units.

Alex.