A device for monitoring the level of salt in a brine tank. The device includes a housing and a circuit within the housing connectable to an electric power source. An indicator is connectable to the circuit for indicating the existence of a first electrical state and a second electrical state. An actuator member is provided having a first position wherein the indicator member indicates the first electrical state and a second position wherein the indicator member indicates the second electrical condition. A biasing member having a predetermined force biases the actuator member towards the first position. A surface member is provided for resting on the upper surface of the material in the tank, the surface member having a weight greater than the predetermined force of the biasing member and a density greater than water. The surface member is movable in the brine tank as the height of salt therein descends, and is connected to the actuator member, wherein the weight of the surface member causes the actuator member to move to the second position when the surface member descends a predetermined distance.