The MiniPond 12000 is a popular box pond filter that features a 6 stage filtration system. It is suitable for ponds up to 12000L without fish. See the size chart below based to determine suitability based on your pond setup. It features a UV light to help kill green water algae, a hinged lid for easy cleaning and multi stage media for optimum water clearning. Filtering stage overview: Graded foam filter pads remove dirt and waste. Ceramic biological filter media prevents the build up of harmful toxins in the pond.Replaceable polymer wool pads removes fine waste particles and polishes the water.Carbon impregnated pad removes chemical pollutants. Features: Comes with 9w UV bulb. Low maintenance and easy to clean. Sixstage filter design. Bio-media and polymer carbon cartridge. Hinged lid allows easy access for cleaning. Flow rate: 3000 Lph Max pond size (without fish): 12000L Recommended Hose sizes: Filter inlet hose from pump: 25mm / 1\" Filter outlet hoseto pump: 40mm / 1.5\" Pond Capacity Guide: Over 75cm deep without fish in shade Over 75cm deep with fish in shade Under 75cm deep with fish in shade Over 75cm deep with fish in full sun Under 75cm deep with fish in full sun Under 75cm deep with koi in full sun 12000 ltrs / 2640 gal 6000 ltrs / 1320 gal 4500 ltrs / 990 gal 4500 ltrs / 990 gal 3375 ltrs / 742 gal 1685 ltrs / 371 gal