I have two level sensors, one is the one with the float (white) and is Sensor #1. This is used for switching on a socket to do Auto Top Ups currently.

The other sensor is a black sensor with a bulb on it, and is attached to the same probe holder yet higher. I would like to use this as an alarm if the water level is too high for some reason.

How do i go about setting this up? Currently Sensor #2 is disabled.