A pond filter arrangement comprising a pond filter (1) comprising a housing having a fluid inlet (12) and a fluid outlet (13) and a chamber (16) within the housing holding a plurality of filter media elements (2) which is disposed in a flow path between the inlet (12) and the outlet (13). Agitation members (41) are disposed in the chamber for agitating carried filter media elements in a cleaning process. The filter media elements (2) are compressible open celled foam portions which, under action of the agitation members (41), are free to change location within the chamber and move relative to one another.
