If you see red and orange stains in your bath tub, sinks and toilets don’t worry because you are not alone. The culprit is dissolved iron in your tap water and it is a very common problem that many people have experienced at one time or another. Fortunately there are several whole house water filtration methods that can effectively remove iron from the water and protect your home from unsightly iron and rust stains.
What is Iron and Why is it in My Water?
Iron is a natural element and one of the most abundant substances in the world. It exists in the soil and is naturally found in rivers, lakes and underground water sources. Since these are also the primary sources where city water companies draw their water from, there is always going to be some level of iron in our tap water. Corrosive water can also pick up iron from old water pipes, so there is no real guarantee that water purified by your city will still be iron-free by the time it arrives to your home. For people on well water, some levels of iron contamination can also be expected because it is commonly found in all natural water sources.
Problems Caused by Iron in Your Water
Iron is an essential trace element that enables the hemoglobin in the red blood cells to deliver oxygen to the rest of the body. Iron is required by our bodies to function correctly and in small amounts it is good for our health; however at larger concentrations it can be toxic and cause severe organ damage and even death. Fortunately the levels of iron found in most city water supplies are relatively low and are not considered a health hazard. One of the most common complaints about iron has to do with iron staining which can leave orange, red and brown stains on sinks, showers and plumbing fixtures. These stains are hard to remove and can even discolor dishes and ruin laundry and clothes. Iron can also add a metallic taste to the water which would affect the quality of people’s cooking, ruining their food and beverages.
Different Forms of Iron
Iron that occurs in water can be found in three primary forms: ferrous, ferric and bacterial iron. All of these forms of iron can cause red iron staining. Ferrous is dissolved iron in clear water that has not been exposed to chlorine or oxygen, and it is in a form that can easily pass through standard water filters. Ferrous iron is more commonly found in natural well water that has not been chlorinated. When ferrous iron is exposed to oxygen or chlorine, it oxidizes and precipitates out of the water to become ferric iron. Ferric iron is found in a particulate flake form and can be removed from the water with a whole house carbon/sediment filter. Iron bacteria are organisms that consume iron for survival and they can produce a red or brown slime known as a biofilm. While this form of bacteria is not a health concern, they are a nuisance that should be sanitized and removed from you water supply.
Iron Treatment Methods
Ferrous iron can be removed by a traditional salt-based ion-exchange water softener up to 5 mg/L. Since iron can also plug and foul the softener’s resin media if not carefully maintained, a water softener is not the best method for treating iron. A more effective option would be to use a specially designed whole house iron filter that uses manganese dioxide media to treat ferrous iron. Manganese dioxide iron filters can typically treat up to 15 mg/L of iron in water by oxidizing and converting ferrous iron into ferric iron which can then be removed easily with a carbon/sediment filter. This type of filter is also highly effective at treating hydrogen sulfide and manganese through the same oxidation process. If iron-bacteria is present in the water, a shock chlorination treatment should be circulated throughout the water delivery pipes in the home to deactivate the bacteria. Once the contamination has been removed, a whole house UV system can be installed to ensure that future iron bacteria growth and breakouts do not occur.
