Does a water softener remove iron from well water?
Like calcium and magnesium, iron has a cationic charge. As a result, water softeners that use ion-exchange technology can attract and remove some dissolved iron from well water.
Because it only takes very small amounts of iron to cause discoloration, metallic tastes, or appliance staining, a softener may therefore help to fix iron issues in homes with mild well contamination.
However, the design of ion-exchange softeners and the salt solutions they use mean that most water softeners will not remove iron concentrations over 2 PPM.
The ability of softeners to remove iron is also dependent upon water hardness. In fact, due to the nature of the ionic reactions that occur inside a softener resin bed, softener systems are only likely to work for iron contamination if the well water is hard.
Water softeners do not remove all types of iron contamination
However, no water softener will remove undissolved iron. Undissolved or ferric iron is insoluble, meaning that it’s carried along inside the water supply without being chemically bonded to water molecules. As a result, undissolved iron won’t be attracted to the salt in the softener resin bed.
Water softeners also do not remove or protect against the growth of iron bacteria. Iron-rich water can be a breeding ground for classes of bacteria that metabolize iron, resulting in water stagnation.
To find out how to set up a comprehensive iron removal system, read our explainer article: How to remove iron from well water.