One of our favourite projects, this natural outdoor pool is 20m long x 4m wide, 1m-2.4m deep and holds around 50,000 lt water! The water is 100% chemical-free and is filtered through the plant/reed/gravel beds around the outside. It took two seasons for the water to become perfectly clear as it takes time for the whole biosphere of the pond to become fully naturalised. There is a pumping system which circulates the water through the various zones. The plants draw nutrients from the water to grow which purifies the water. The vegetation is then cut down in the winter so the plant mass can't decay back into the water. The gravel beds work off two fronts, one mechanically filtering debris from the water and two, other bacteria. The gravel is colonised by positive bacteria which again strip nutrients from the water. The circulation of the water creates oxygen which feeds the micro-organisms.