Blagdon 20000 Litre Midipond UV Pond FilterUV pond filter system with crystal clear water guaranteed 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 High performance UVC clears green water algae 3 Year