Principally,the system consists of a seriers of connected tanks receiving the water coming from the individual processing stages. Special submersed pumps lift the water to the poker filters placed on the scaffolding over the tanks. The water thus filtered is delivered to its use and returns to the tank of provenance. Thus it is possible to recycle the same water continuously without any waste or within tolerable limits, anyhow. Any loss in the system is integrated with a slight quantity of clean water let in by means of an automatic level control system.