Abstract: A rotary disc filter having a backwash system that includes a series of feed pipes that project into and between successive filter discs that are mounted on a rotatable drum. Connected to an outer terminal end portion of the feed pipes is a series of nozzle holders. Each nozzle holder includes a main conduit, a series of branch conduits that project outwardly from the main conduit, and a connector for connecting the nozzle holder to a respective feed pipe. A series of detachable nozzles are secured to the outer terminal ends of the branch conduits.