If your AquaPurr eC3 is turning on and off by itself, you need to reduce the range.

1.  Lift the lid off the AquaPurr

2.  Pop the back off the sensor

3.  Turn the adjustment screw counterclockwise to reduce the sensor range.

If you hit a stop point when turning the adjustment screw counterclockwise, then turn the adjustment screw clockwise 1/8 to 1/4 turn to reset the sensor range to 6-12"