Doulton Drinking Water Systems- Ceramic Water Filters Second to None. Complete line of Doulton ceramic water purification systems- filters and purifiers for residential, industrial use, travel, marine purposes, disasters, emergency situations. Boats / RV's fresh water systems. British Berkefeld portable gravity drip water purifiers. Food / Pharmaceutical Industry stainless steel ceramic cartridge filters. Commercial Kitchens Equipment. System designed for "problem drinking waters" such as chemical, microbiological, heavy metal plus a choice of the following cartridges: Nitrate, arsenic, fluoride and MTBE reduction.