Usually the problem with skimmers is if the water level is too high. The issue is the current, not the voltage. Float switches can only handle very low current loads. The coils in relays can also cause voltage spikes when the switch on and off. You’d be best off having an interface between the float switch and the relay.Need some help with a relay.
I want to run a USB air pump to run a skimmer but I want to have it shut off if the water level drops too low. Is there a 5 volt relay that can work off a float switch?