Mechanical and Biological Filtration. The Bermuda Pressure Filter 5000 has a compact design that combines mechanical and biological filtration with an in-built 9 Watt Ultra Violet Clarifier for crystal clear water. Being a pressurised unit, water can be pumped uphill out of the unit to feed water courses or return to the pond while the filter remains hidden. Key Features Easy to install Compact design Bury in the ground Built-in 9 watt UVC For ponds up to 5,000 litres Specifications Max Pond Volume: 5000 litres / 1,100 gals Recommended Pump: 3,500lph/770gph UV: 9W