A WATER SOFTENER CAN REDUCE IRON TO BELOW THE THRESHOLD OF STAINING, BUT IT CAN NOT TOTALLY REMOVE IT! Under some circumstances, a water softener will work for a while, but the resin bed will gradually become fouled with iron over months or years, decreasing it’s efficiency at removing the iron. To totally remove iron, one must utilize the following:(1) Oxidation and filtration; or (2) Sequestration using polyphosphates.
POLYPHOSPHATES – We will discuss sequestration of iron with polyphosphates first. Sequestration of iron with polyphosphates does not remove it from the water supply, but keeps the iron in solution, so that it does not produce stains. This is often used when individuals or businesses want to keep the iron from staining in irrigation systems. It is accomplished by injecting a small amount of polyphosphate into the water, typically with a chemical injection pump and a solution tank containing a supply of polyphosphate. However, it is not perfect in removing iron, as evaporation of the water can still leave an iron residue and the iron often precipitates when the water is heated. Results may very dramatically with sequestration, depending upon a variety of factors, not the least of which is water chemistry.
OXIDATION – Almost any concentration of iron can be oxidized by feeding an oxidizer such as chlorine, ozone, potasium permanganate, hydrogen peroxide or even oxygen into the water supply. The oxidizer reduces the iron to a small particle (precipitate), which is then mechanically filtered from the water, typically by a backwashing filter with a dense media containing carbon or materials.
In my thirty-plus years of experience, I have personally tried every method known to man to remove iron. Today, I primarily tried use hydrogen peroxide, as it is a much better oxidizer of iron than either chlorine or potassium permanganate and does not leave excess air in the water like oxygen systems. Unlike chlorine, hydrogen peroxide is simply hydrogen and oxygen and produces no harmful chlorination byproducts. A hydrogen peroxide system consists of a chemical injection pump, solution tank, in-line static mixer, and a backwashing filter to remove the oxidized iron.
I prefer the hydrogen peroxide system because it completely removes iron and sulfur with totally predictable results. It is my opinion that other methods are not as predictable or reliable in function. A hydrogen peroxide system will remove 100% of the iron. PERIOD! For homebuilders that build large custom homes with irrigation systems on iron-bearing waters, the hydrogen peroxide system will totally eliminate any staining in irrigation systems, and throughout the home, for that matter. Additionally, a water softener will not have to work nearly as hard once the iron is completely removed. This is not to say that other methods can’t work. I am just stating my opinion based upon my extensive experience in treating problem water.