Abstract: A diffuser rod for use in a filter stalk having deflector disks rigidly mounted thereon to deflect liquid radially during the backwash process is disclosed. A backwashable filter element containing a diffuser plate that is located within the filter member at the end where the backwash fluid enters the filter member and a number of filter stalks with each filter stalk including a diffuser rod is disclosed. Finally, a method of backwashing a filter member that includes the step of introducing a diffuser rod and a diffuser plate to the filter assembly is disclosed.