Two-point control (pump on-off) by two probes of different length "Pump on" if both probes are out of water, "pump off" if both probes are immersed.
Feed control with one probe and one (external) time relay. Only one probe (rod) is needed for pump control. "Pump on" if the probe is out of water and at the same time start of an external time relay. After an adjusted time, the time relay switches "pump off".
Outlet control (flow-off) by two probes of different length "Valve open" when both probes are immersed, "valve closed" when both probes are out of water.