Typically, monitor probes for the waste water system are connected to the side of the tank by drilling a hole, inserting the probe and wire, and tightening the screw. As the waste water level rises, the probes “arc” across and send the signal to the panel for the different levels. Impurities in the water, toilet paper, and other contaminants can create a constant “arc” even when empty. Using the proper toilet paper and probe cleaning products can reduce this.