I have a issue I was wanting to put out there. I have a 100 gal saltwater aquarium with a sump underneath. I woke up this morning to find my siphon pump had failed and my main water pump was running dry. I would like to make an auto pump shut-off and basically I want to interupt the AC power to the pump when the water level reaches a certain point. I have a float valve that works, I haven't had a chance to put a meter on it but I believe it works on the principle of high resistance closed, low resistance when open. Any thoughts of doing this safely?