And "poor bactericide" means that it does not kill nor even inhibit fecal bacteria at all and only kills non-fecal bacteria slowly (except for Legionella). See this post for technical details. If you absolutely have to use a metal ion system and don't care about staining or blond hair turning greenish, then at least use a copper/silver ion combination since that will at least prevent uncontrolled bacterial growth of even fecal bacteria though you still won't have any reasonable protection against viruses or protozoa.