An ideal filter for ponds up to 2600 gallons; koi ponds up to 1330 gallons.  Steps-wise transition from mechanical filtration to high efficiency biological filtration.  Section 1 is the Sedimentation Chamber - water inlet and large particle sedimentation.  Optional UVC can prevent blooms of unicellular algae, bacteria, and parasites.  Section 2-3-4 contain Matala media in varying densities.  Section 5 is Fuji Stone for nitrification, dentrification, and buffering of pH and water mineral contents.  Section 6 is polishing chamber for water conditioning and polishing.  Recommended flow of 665 gph.  Inlet 1" to 1 1/2" barb; outlet 2" slip.  Sludge outlet 1 1/4" to 1 1/2" barb with plug.  Ideal flow rate 1500 gph.