The MidiPond 28000 is a popular box pond filter that features a 7 stage filtration system. It is suitable for ponds up to 28000L 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: Spray bar oxygenates water creating the ideal environment for friendly bacteria. 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 24w UV bulb. Low maintenance and easy to clean. Spray bar oxygenates water creating the ideal environment for friendly bacteria. Seven stage filter design. Bio-media and polymer carbon cartridge. Hinged lid allows easy access for cleaning. Flow rate: 7000 Lph Max pond size (without fish): 28000L Recommended Hose sizes: Filter inlet hose from pump: 40mm / 1.5\" Filter outlet hose to pump: 4 x 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 28000 ltrs / 6159 gal 14000 ltrs / 3080 gal 10500 ltrs / 2310 gal 10500 ltrs / 2310 gal 7875 ltrs / 1732 gal 3935 ltrs / 870 gal