A pool or spa system includes networked pool or spa devices that can be dynamically configured with network addresses by a controller. The controller can transmit a device discovery request on a network and can receive a discovery response from pool or spa devices that require a network address. The system determines and assigns the network addresses for the pool or spa devices based on unique device identifiers associated with the responding pool or spa devices. The network addresses assigned to the pool or spa device are transmitted to the pool or spa device to be used by the pool or spa devices to communicate with the controller over the network. The system can be used to discover and assign addresses to various types of pool or spa devices, such as pumps, underwater lights, chlorinators, water feature controllers, remote controllers, and/or other types of devices.