Mineralisation on calcium/magnesium carbonate filter by Water Systems: already widely used on boats to mineralize demineralised RO sea water, the process includes water acidification equipment by means of CO2, necessary to acidify the demineralised water (carbonic acid formation) in order to give it the properties necessary to dissolve the calcium carbonate in follow stage of treatment. Filter contains a layer composed of calcium and magnesium carbonate: the passage of acid water through the filter layer will determine the dissolution of the salt contained in the filter and therefore the mineralization of the filtered water. To ensure exchange surface between liquid and solid, minerals used in the filters have a particle size of 0.8÷1.2 mm, and the inorganic layer will be installed on a siliceous sand layer to avoid leakage of fine stuff. The process is continuously controlled by pH analyzer and conductivity analyzer. The equipment is completely manufactured in Aisi 316 L stainless steel and provided with salts powder dissolving tank and centrifugal pump for the transferring of the concentrate to the storage tank.