A device, system, and a method are provided for notifying a user to replace a sacrificial anode in a pool or spa system. The device is provided in the form of a body defining a cavity, a sacrificial anode, and a sensor. The sacrificial anode substantially surrounds the cavity when the sacrificial anode is coupled to the body. The sensor is at least partially received into the cavity and is in communication with a pool automation system. The sensor is designed to transmit a signal to the pool automation system when the sensor detects water within the cavity. The signal is processed by the pool automation system, and the pool automation system may then transmit a notification to a user that the sacrificial anode is depleted.