Iron/Manganese Filter

Water that is clear when drawn but changes quickly to a yellow or rusty color upon standing indicates presence of ferrous or clear water iron. Iron is found in water in two different forms i.e., soluble, chelated. Iron in its ferrous state is very soluble in water. This iron has not yet been exposed to oxygen and therefore is not “rusted” or oxidized, is totally dissolved in water. However, when exposed to air, it is oxidizes and convert to insoluble ferric form which gives yellow brown colour in water and forms staining color on the surface of sinks, toilets, showers and other plumbing fixtures.

Iron may also be present in water in combination with organic matter. Many natural and man-made organic compounds will react, particularly with ferrous iron, to form heavily colored compounds which can cause severe staining. Water may also produce stains by the action of iron bacteria (living organisms), which feed on iron in water, iron pipes and fittings. They pose no health risk but can be very damaging to the plumbing system. These bacteria form a reddish-brown slime, which may clog pipes and fixtures.

Iron may be found alone or associated with manganese, H₂S and hardness which collectively increases the severity of the problem.

Manganese is very similar to iron in its properties. In fact, they both often occur together with manganese composing a small part of the combination. Manganese can occur in a clear water state, later turning to a colored water state. There are also manganese bacteria which are similar to iron bacteria. Manganese staining does often appear to be darker than iron staining (sometimes black). The distinction between iron and manganese is usually not that important because most methods which successfully treat iron will also treat manganese.