I agree the tank sensors are somewhat of a joke. Once you start using your rig and if you draw water from your fresh tank you will know where you are at without the sensors. I have found the tank full sensor to be the one that is most often working so that can be handy. On my rig's I know I can handle all the water in the fresh tank so I can just dump when I am running out of water. I equalize my tanks when necessary so I know I won't overflow. The fresh water tank is usually pretty accurate cause there ain't no solids in it!
