A compact but highly efficient pressurised filter, which on the larger models have a unique self cleaning system. All the filters contain profiled filter sponges (6) for mechanical filtration, Fish Mate SUPRA media (7) for biological filtration and an appropriatly sized Ultra Violet bulb (4). The water firstly passes over the bulb where the green water algae is flocculated (clumped together), then flows through the settlement chamber (5) and then up and through the filter sponges, which catch the particles in the water. Lastly the water passes around the SUPRA filter media, where the friendly bacteria undertake biological filtration. All units are supplied with 5m of cable (9). The UV lamp indicator (3) allows at a glance view of whether the bulb is working or not. The lid is secured by a single clamp ring (8) allowing easy access for filter maintenance. Inlet hosetails (1 & 10) take 19, 25 and 32mm hose. POWERCLENZ is the patented automatic cleaning system included in the 10000 and 15000 models. These units clean the filter sponges by utilising the power of the pump, in reverse. A control knob on top of each unit (P) alters the water direction within the filter so that instead of water flowing up through the sponges it flows down. This flow pushes the SUPRA container compressing the sponges and squeezing out the waste. The dirty water is then routed out of the third outlet (S), which was opened when the control knob was turned, and can be directed off through suitable hose (not supplied). For this option to be effective it must be done regularly if the filter is left too long the waste will compact and will not be removed by the reverse flow.