Abstract: Conglomerations of charged ions of minerals in a water pipe system resulting from subjecting the water to an alternating electric field are effectively removed from the water flow path by providing first and second screens. The first screen is located normal to the flow path so that the water flows through the screen. The second screen is located in a chamber connected laterally to a water pipe section carrying the water flow upstream of the first screen. The first and second screens are charged positively and negatively respectively so that the first screen will repel conglomerations of minerals and the second screen will attract the same to collect them in the chamber.