KDF water filter could eliminate 99 heave metal ion dissolved in water, such as Cl^-1, Pb⁺²,Hg⁺²,Ni⁺³,Cr⁺³,and other harmful ions in water. It has remarkable effectiveness to remove germ and epiphyte in water,also it could restraint algae to glow,reduce mineral substance which might be form scale. Filtering element of this filter is made of high purity of copper and zinc grains. Its working principle is based on electrochemical oxidation  and deoxidization(transfer electron between filtering elements and heave metal ion) to purify water. This filter is mainly applicable for potable water processing, water preprocessing before RO system or processing waste water. This is a newly designed product to replace existing filter technologies. It would remarkably prolong using life of water treatment system, reduce heave metal ions, germ and scale in the system, reduce total investment,saving labor.