Neither iron or manganese in water present a health hazard, however their presence in water may cause taste, staining and accumulation problems. Because iron and manganese are chemically similar, they cause similar problems.
Iron will cause reddish-brown staining of laundry, porcelain, dishes, utensils and even glassware.
Manganese causes a brownish-black stain.
Soaps and detergents do not remove these stains, and the use of chlorine bleach and alkaline builders (such as sodium carbonate) can actually intensify the stains. Iron and manganese deposits will build up in pipelines, pressure tanks, heaters and UV light disinfection systems — reducing the available quantity and pressure of the water supply and affecting the disinfection performance of UV systems.