EXTREME 50 is an external mechanical-biological filter designed for water ponds up to 50,000 liters. It is designed to operate with a water pump with maximum efficiency up to 15,000 l / h (PFN 15 000).The optimal flow of water through the EXTREME 50 filter is 8000 - 15000 l / h. Water flows through the filter and leaves on the individual layers mechanical impurities and toxic substances. The filter provides excellent conditions for the development of micro-organisms (protozoa, bacteria and other microorganisms) that normally live in the pond, while they are safe in the filter and can grow in large colonies. In return for constant supply of oxygen and food, these organisms purify water flowing through the filter. It is a powerful mechanical, biological and chemical filtration. It also includes zeolit, which absorbs toxic ammonia – which could be very dangerous for the fish.