A wastewater filter assembly comprising a filter having an influent side and an effluent side, a backwash system adapted to control flow of backwash fluid from the effluent side to the influent side, and an agitation system adapted to control the flow of an agitating fluid (e.g., air) from the influent side to the effluent side. In one embodiment, the agitation system includes an agitating tank that stores the agitating fluid, and a series of valves to control the flow of backwash fluid and agitating fluid. In another embodiment, the assembly further includes a control system that controls the backwash system and the agitation system. Preferably, the control system is programmed to pulse the agitation system during operation of the backwash system.