For well water owners, the presence of unwanted elements in the water supply is not an unfamiliar nuisance and can require much strategy and preparation to resolve.
Iron is a very prominent element in groundwater and can cause many problems to a well owner’s water system if left untreated.
It is imperative that proper understanding of the iron problem is first established before attempting to treat it as there can be lots of time and money wasted on setting up equipment that might not address the issue correctly.
This article aims to bring education and understanding on how to correctly identify the iron problem, how to properly treat the issue with the right filtration system, and to answer any questions one may have about how to remove iron from well water.
This article will discuss the following:
- How to Find the Right Water Treatment for Iron Removal
- How Iron Gets into the Water Supply
- Health and Plumbing Concerns About Iron
- Types of Iron Found in Well Water
- How to Test for Iron
- Reviews of the Best Iron Filters for Well Water
Editor's Choice for Best Iron Filter for Well Water
- Finding the Right Water Treatment for Iron Removal
- Understanding Iron
- How to Test for Iron in Well Water
- The Role of Alkalinity (pH) in Iron Removal
- The Best Iron Filter for Well Water
Finding the Right Water Treatment for Iron Removal
Finding the most efficient method of removing iron largely depends on the conditions of the water supply. These conditions include the level of concentration in ppm, the type of iron present in the water, and pH level of the water supply. The following will cover several different methods for removing iron and the conditions the water should be in in order for these methods to work.
For Iron Concentrations Less than 3 ppm
Water softeners work through an ion-exchange process where elements such as iron, magnesium, and calcium are collected and exchanged with sodium. For well water with a low enough concentration of ferrous iron (less than 3 ppm) and a pH level no greater than 6.7, the ion exchange process is an effective way to remove iron from a water supply.
Water softeners should not be used with a well water supply containing ferric iron as it is invalid for ion exchange and can quickly foul the resin beads, nor should a softener be used to remove ferrous iron in concentrations higher than 3ppm as the resin beads may not be strong enough to pull such high concentrations of iron.
Alkalinity is also a factor to consider since the higher the pH, the likelier ferrous iron will oxidize into ferric iron and become invalid for ion exchange. To learn more, read our article on water softeners for well water systems.
For Iron Concentrations Greater than 3 ppm
For concentrations of iron that a water softener would not be able to remove, an iron filter will be necessary. Iron filters work through a process called oxidation.
Because ferrous iron is soluble and easily passes through any filter, it must first be “oxidized” into ferric iron and then filtered. Once in the insoluble ferric state, the iron can be filtered through a variety of different media before clean water passes through the outlet.
The oxidation process can happen by a variety of methods but the most common are with air, media, or chemicals.
Often called Air-Injection, Air-Induction, or Chemical-Free Iron Filters, this method of oxidation uses pressurized air to oxidize the iron into the insoluble ferric state that can be filtered.
Within an air injection iron filter tank are air, water, and a media bed. As iron-concentrated water passes through the tank, the ferrous iron is oxidized by the air and then filtered through the media bed where it remains. Clean, iron-free water is passed through the tank and into the outlet.
The ferric iron within the media bed is then backwashed and flushed from the system through the drain pipe.
Air injection iron filters also oxidize and filter manganese and hydrogen sulfide in the same fashion.
Media and Chemical Oxidation
Greensand Filters - Manganese Greensand, characterized by its often greenish-hue, is one of the oldest medium used to oxidize and remove iron from a water supply. Iron is immediately oxidized and trapped as it passes through a greensand filter allowing clean water to filter through.
Greensand filters require Potassium Permanganate, a strong oxidizing agent which regenerates the greensand periodically after use.
Birm Filters - Birm, a granular media filter named by the company who invented it, works similarly to greensand in that it oxidizes ferrous iron immediately as it comes into contact with it. Unlike greensand filters, Birm filters do not require additional chemicals to regenerate the media, rather, the media is automatically and periodically backwashed.
Chemical Feed Pumping
In extreme cases, and cases which involve iron bacteria, iron filters and water softeners might not be the most effective application in solving the iron problem. Certain chemicals may need to be pumping into the well supply in order to combat specific contaminants. In this case, a chemical feed pump is required.
Chemical feed pumping works by injecting certain chemicals into the well itself with the purpose of eliminating, oxidizing, or disinfecting specific contaminants within the water supply. A professional contractor should be consulted when considering chemical feed pumping as the task itself involves a number of nuances that can potentially be overlooked.
While iron filters are very effective at removing iron at the surface level just before it enters the home, chemical feed pumping attacks the iron problem at the source. Chemical feed pumping is a much more permanent solution and can rid the iron problem before it reaches the house once and for all.
The most common chemicals used are:
- Chlorine to treat Iron Bacteria and to oxidize Iron
- Hydrogen Peroxide to treat Hydrogen Sulfide and to oxidize Iron
- Citric Acid to lower the water’s pH level
- Sodium Carbonate to raise a water’s pH level
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How Does Iron Get Into Well Water?
Making up 5% of the earth’s crust, Iron is the 2nd most abundant metal and the 4th most abundant element within it. As rainwater seeps into the soil penetrating the outer layer, iron within the earth’s crust dissolves into the aquifers and settles in the groundwater beneath us.
While certain regions around the earth may have higher concentrations of Iron in the groundwater than others depending on the geological terrain, Iron is often found in concentrations between 0.5 to 10mg per liter.
What Are the Effects of Having Too Much Iron in Well Water?
Iron is an essential element to living organisms, necessary for survival, and is therefore not considered a harmful contaminant in drinking water. In fact, many people are Iron deficient, lacking the adequate amounts of iron from their diet.
While concentrations of Iron in well water are rarely higher than 10 ppm, acute iron toxicity is a possibility when ingesting Iron at concentrations higher than 10 ppm and are usually associated with abdominal pain and headaches. With that said, Iron toxicity is usually related to excessive intake in the form of supplements rather than from the consumption of well water.
High concentrations of iron are more of a concern for the well water system itself as numerous problems can arise when left untreated.
Iron can greatly affect the taste of water and food, leaving a very unpleasant metallic flavor. It may also leave an inky, black deposit when mixed with tea and other beverages, and can turn vegetables dark.
Iron in concentrations as low as 0.3 ppm can leave reddish-brown stains in bathtubs, sinks, fixtures, and laundry which are very difficult to remove.
- Untreated iron can also leave deposits within the water pipes which can potentially cause blockage and severe damage to the well system as a whole. Iron can also be seen coming through faucets and showerheads, giving an unpleasant orange tinge to the water supply.
Know the Types of Iron in Well Water
Ferric Iron, also known as red-water iron, is characterized by the reddish-orange hue it gives to water. Because it has been oxidized and solidified within the water, it is easier to identify and much easier to eliminate through a filtration system.
Ferrous iron, also known as clear-water iron, is invisible to the naked eye as it is fully dissolved into the water – only its negative effects on the water system are observed. Ferrous iron is unfilterable, however low levels of ferrous iron can be captured through an ion-exchange system such as a water softener. Higher levels of ferrous iron must be converted into ferric iron through oxidation and then passed through a filtration system.
Iron bacteria are tiny microorganisms that feed on ferrous iron within the water and leave behind a metabolized, slimy, orange sludge inside toilet tanks and within water pipes. In most cases, the elimination of the iron itself will resolve the iron bacteria problem as it removes their source of food. In extreme cases, chlorine treatment may be needed to disinfect the water supply of the bacteria.
How to Test for Iron in Well Water
Iron, as with all other elements found in water, is measured in milligrams per liter (mg/L) and can equivalently be expressed as parts per million (ppm).
mg/L = ppm
For example, an iron level of 3mg/L means that for every liter of water, 3 milligrams of iron will be found. This is equivalent to 3 parts per million (3 ppm).
Ferric iron is visible to the naked eye and in high concentrations can be observed flowing from the tap in an orange hue or stained against the sink and bathtub. In lower concentrations, ferric iron can settle at the bottle of a glass of tap water after sitting for several minutes.
Iron bacteria is characterized by an orange sludge that accumulates inside the toilet tank or in areas where water is collected.
While the visual test is easy and inexpensive, it would only indicate whether or not iron is present and not the level of concentration.
Home water test kits typically come in the form tablets or liquid that are dropped into the water or in the form of strips which are dipped into the water. Many test kits test for many other contaminants as well as iron which will be helpful in understanding the most effective method in treating the water. These tests often have their own color-coded guidelines in determining the presence of the various contaminants.
The most accurate and efficient way to find out the exact concentration and variety of contaminants in the well water supply is to have it tested by a laboratory. Many water testing laboratories will send out test kits that may be sent back with sample specimens from the water supply. Others may have professional testers that arrive at one’s home to test the water in person.
While lab testing is much more expensive than home test kits, it is by far the most reliable and accurate.
Other Contaminants to Test For
Manganese and Iron are both common elements in groundwater and where one is present, the other is often as well. While Manganese levels aren’t usually as concentrated as Iron, it can stain laundry and appliances just as well but with a black tint instead of red. Manganese can be removed in the same fashion as iron which will be discussed in the later section of this article.
While Hydrogen Sulfide is invisible to the naked eye, it is quite noticeable by its rotten-egg odor which is highly unpleasant. Hydrogen Sulfide exists as a biproduct of sulfates which react with magnesium in the water. Hydrogen sulfide is removed in the same fashion as iron through a process known as oxidation.
The Role of Alkalinity (pH) in Iron Removal
The pH level of a water supply is an important factor in the iron removal process as it determines the ease at which ferrous iron converts to ferric iron. The higher the pH level of the water, the quicker iron oxidizes into its ferric state.
For iron filters, a pH level of at least 7.0 is recommended by most manufacturers as it allows the oxidation to happen fast enough for the ferric iron to be filtered.
For water softeners, a lower pH level is recommended as the iron must remain in its ferrous state in order for ion exchange to occur.
Video: How to Remove Iron from Well Water
Watch this informative video from Fresh Water System about removing iron from well water.
The Best Iron Filter for Well Water
(Which Application Fits Me Best?)
Finding the best iron filter application for a well water system will require some necessary information beforehand. Knowing the level of concentration of iron, the presence of other contaminants, and the pH level of the water is important in determining whether an iron filter, a water softener, or whole house filter is best for your system.
The following applications are paired with the most common scenarios.
For Iron Levels > 3 ppm, pH levels > 7.0, + Manganese and Hydrogen Sulfide
- Air Injection Iron Filter
- Removes Iron up to 27 ppm
- Removes Manganese up to 11 ppm
- Removes Hydrogen Sulfide up to 17 ppm
- Fleck 2510SXT Digital Air Injection Control
- Peak Flow: 12 GPM
- NSF and WQA Certified
The Platinum 15 Air Injection unit by AFW Filters removes the highest level of Iron on this list at 27 ppm. While it isn't common to find Iron in well systems at concentrations that high, one can rest completely assured that their home will have no red stains or any rotten egg smell.
The Platinum 15 removes iron, manganese, and hydrogen sulfide at high concentrations using a patented air injection system to oxidize the contaminants, as well as a manganese-dioxide based media bed for further oxidation and filtering. The combination of air and media for oxidation allows for the collection of such high concentrations of contaminants.
The Platinum 15 can accommodate a large household of 4+ people with 3+ bathrooms. The automatic backwash cycle regularly drains the tank of contaminants for cleaning, allowing for more filtering to be done. The single tank unit involves a minimal amount of moving pieces for ensure stability and low maintenance.
The digital control unit by Fleck allows for cycle programming and viewing system status at a glance. A bypass valve with 1" connection is available for easy shut-off.
AFWFilters has over 35 years of experience in water filtration and is both NSF and WQA certified. They have mastered the Iron process with their Platinum 15 model, providing priceless peace of mind for homeowners worldwide.
For well systems with an extremely high concentration of iron, manganese, and hydrogen sulfide, and with pH levels greater than 7.0, the Platinum 15 may be the perfect solution.
More in this series:
- Air Injection Iron Filter
- Removes Iron up to 10 ppm
- Removes Manganese up to 2 ppm
- Removes Hydrogen Sulfide up to 12 ppm
- Fleck 2510SXT Digital Air Injection Control
- Peak Flow: 10 GPM
- NSF and WQA Certified
The Silver 10 Air Injection Iron Filter by AFWFilters is identical to the Platinum 15 model in function and build, but designed to accommodate average-sized homes with slightly lower concentrations of contaminants.
If iron concentrations are less than 10 ppm, which in most cases it will be, the Silver 10 is more than powerful enough to eliminate iron, manganese, and hydrogen sulfide.
Designed for homes of 2-4 people, the Silver 10 is a smaller version of the Platinum 15 but utilizes the same technology which put these Iron Filters at the top of our list.
- Air Injection Iron Filter
- Removes Iron up to 12 ppm
- Removes Manganese up to 2 ppm
- Removes Hydrogen Sulfide up to 10 ppm
- Fleck 2510SXT Digital Air Injection Control
The Iron Eater by Durawater is a popular, durable, well-reviewed iron removal system which uses air injection technology. Removing up to 12 ppm of iron, 10 ppm of hydrogen sulfide, and 2 ppm of manganese, the Iron Eater is more than capable of removing problematic contaminants for most well owners.
For Iron Levels < 3 PPM, pH levels > 7.0, + Manganese
- 100,000 Gallon Capacity
- Removes Iron up to 3 ppm
- Removes Manganese up to 1 ppm
- Removes up to 95% of sediment, chlorine, VOCs, and pesticides
- Peak Flow: 15 GPM
- PSI Range: 25 - 80 psi
Some households are looking to invest in a whole house filter for additional contaminants such as sediment, pesticides, and VOCs but don't have iron concentrations high enough to warrant purchasing an entire iron filter. In this case, a whole house filter with a second stage for iron and manganese filtration may work perfectly.
If iron concentrations are less than 3 ppm, the 2-stage whole house filter by iSpring will filter out iron and manganese in addition to sediment, chlorine, pesticides, and herbicides. It is often recommended for iron filters alone to be accompanied with a carbon filter to trap sediment and other contaminants that the iron filter won't catch. This model by iSpring combines both iron filter and carbon filter into one unit.
Filtering out 95% of contaminants, and with a 100,000 gallon capacity, the ultra-efficient carbon filter won't need replacement for an entire year.
For Ferrous Iron Levels < 8 PPM, pH levels < 7.0, + Manganese and Hydrogen Sulfide
- Removes Ferrous Iron up to 8 ppm
- Removes Manganese up to 6 ppm
- Removes Hydrogen Sulfide up to 2 ppm
- Removes Hardness up to 75 GPG
- 64,000 Grain Capacity
- 10 Year Warranty for Tank
It is not uncommon for groundwater to contain high concentrations of calcium and magnesium in addition to iron. Hard water is characterized by high levels of calcium and magnesium which can calcify within the plumbing system and require costly repairs if not addressed.
For those who are in need of a water softener as well as an iron filter, the Iron Pro 2 solves both problems very efficiently. The combination water softener and iron filter removes hardness up to 75 grains per gallon, iron up to 8 ppm, manganese up to 6 ppm, and hydrogen sulfide up to 2 ppm.
Though it is marketed as an Iron Filter / Water Softener combination system, the Iron Pro 2 is still technically a water softener which removes higher levels of iron than standard water softeners. Because it is a water softener and eliminates contaminants through the ion-exchange process, it should be treated as such. Iron must be in the ferrous state to be exchanged with salt and pH levels must be below 7.0.
More Sizes in this Series:
For Ferrous Iron < 3 PPM, pH levels < 7.0
- 48,000 Grain Capacity
- 12 GPM Flow Rate
- Removes Ferrous Iron up to 3 ppm
There are certain cases where iron is present in low levels, but hardness is much more of a concern. Instead of purchasing an iron filter, a standard water softener will remove hardness in the form of calcium and magnesium, and will remove low levels of iron up to 3 ppm.
Iron must be in the ferrous state in order to be removed through ion-exchange and pH levels must be no greater than 7.0. Be sure to do a water test in order to determine the exact type of iron present in the well and the pH levels thereof.
More Sizes in this Series:
Iron is one of the most prevalent elements in the earth’s crust and it is no wonder how common of an occurrence it is in well water systems. While the iron found in groundwater is largely considered innocuous for human consumption, the damage that iron can cause in home plumbing systems and fixtures can be severely problematic and costly.
There are several different methods for removing iron from a drinking water supply, and while all have their own benefits, it is important to understand the make-up of the water supply in order to correctly apply the right system. Testing the water will determine the levels of iron as well as any other contaminants that may need to be addressed.
Water softeners, iron filters, and chemical feeds are all effective methods for removing iron when used for the right application. Be sure to have proper knowledge of the iron in the water when making a decision about how to remove iron from well water sources.
Thank you for taking the time to read our article on how to remove iron from well water. We'd love to hear your feedback in the comments section below. If you've found this article to be useful and are interested in learning more, be sure to sign up for our newsletter.
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