Iron usually shows up as reddish-brown stains in your tubs and on your faucets, and while it isn’t dangerous, it can cause problems around your home.
If you suspect you may have iron in your well water, this guide will help you find out for sure. It’s easy to test for iron in the water, and you can reduce or eliminate iron using one of several water filtration methods.
Table of Contents
🤔 What Is Iron In Well Water?
Iron is one of the most common well water quality issues.
Elevated iron levels may give your water an orange tinge or leave red stains (rust) in your sink, toilet tanks, and other bathroom fixtures.
Iron is present in the earth’s crust, being one of the most abundant minerals in our soil. Numerous types of iron naturally occur in shallow soils and groundwater, and heavy rainfall can send iron down through the soil into underground well water systems. Melting snow is another cause of iron in well water.
📝 Types of Iron in Well Water
There are three forms of iron in well water:
- Ferrous iron
- Ferric iron and
- Bacterial iron
Ferrous iron is a soluble iron, also known as clear water iron. It’s completely dissolved into the water, and won’t affect water’s taste or smell. This type of iron only becomes noticeable when it’s exposed to the air, which causes it to oxidize.
Ferric iron is insoluble and doesn’t completely dissolve in water. It gives water a brown, red or orange tinge and leaves stains in your sinks, toilet tank, and other plumbing fixtures.
Bacterial iron is formed when iron and bacteria merge, forming a sludgy matter. It’s the worst sort of iron to deal with because it clogs pipes and is difficult to remove.
💡 Effects of Too Much Iron in Your Well Water
There are a few common effects of excess iron in your well water, including:
- Pipe & appliance clogging – Caused by a buildup of iron deposits over time (especially likely with iron bacteria).
- Skin & hair issues – May stain hair orange and increase the likelihood of dry skin and irritation.
- Appliance staining – Reddish-brown stains on your water-using appliances and in your plumbing fixtures, including your sinks and toilet bowl.
- Discolored water – Brown, reddish, or yellow-tinged water leaving your faucet, may be especially apparent in a glass of still water.
- Metallic-tasting food – Foods cooked in water containing iron, and beverages made with iron-laced water, might take on a metallic taste.
🧪 How to Test for Iron in Water?
Knowing how to test for iron is the first step towards cleaner, healthier drinking water.
Here are some of the best methods of detecting iron in water:
Water containing iron may have a red, brown, yellow, or orange tinge. Pour a glass of water to see what color it takes when it’s sitting still.
Soluble ferrous iron doesn’t have distinct color and taste in water and will only oxidize when exposed to the air. To test for this iron type, dip a tissue into a glass of water, then leave it to dry. The oxidized iron will show up on the tissue as rust discoloration.
At-Home Test Kits
At-home test kits cost between $10 and $30 and give you a better understanding of the iron present in your water.
Most kits take less than 5 minutes to give a reading. Simply dip a test strip in your water sample and wait for it to change color, then compare the strip to the color chart.
You need a test kit that can measure iron as high as between 3 and 10 mg/L or PPM, or parts per million.
The most thorough method of iron testing is laboratory testing. Laboratories use expensive testing equipment and the most tried-and-trusted techniques to provide a much more accurate result.
You can find lab tests that test specifically for iron, or for a range of common well water contaminants.
👨🔧 Our recommended laboratory test for iron is the SimpleLab Tap Score groundwater test package. This package tells you not only what type of iron and how much iron is present in your water, but also which competing contaminants are present, so you can choose precisely the right water treatment system for your situation.
✔️ How to Get Rid of Iron in Water
Here’s how to remove iron from well water with the best water treatment solutions.
Ferrous Iron Treatment
Below, we’ve shared the best water treatment systems to remove ferrous iron:
Ion Exchange Water Softeners
Whole-house water softener systems don’t just remove hardness-causing minerals like calcium and magnesium. Many are also effective at removing iron. You can buy a whole house salt-based water softener that will treat well water at its point of entry into your home.
Water softeners use a process known as ion exchange on a charged resin bed. During the ion exchange process, dissolved calcium and magnesium ions bind to the water softener resin, which releases equal amounts of sodium (salt) ions to balance the water’s charge.
This produces salt-softened water, and the unwanted ions are flushed away from the resin when the water softener regenerates.
Water softeners also remove low levels of clear water iron present in a hard water supply. A salt-based softener can remove between 0.3 PPM to 3 PPM of ferrous iron.
Some iron-focused softeners can remove more than this – up to 7.0 PPM of ferrous iron. To facilitate iron removal, increase your water hardness setting by 4 for every 1 PPM of iron detected in your water.
If you have ferric iron in your water, you’ll need to install a sediment pre-filter before your water softener, which will prevent the iron from clogging up the water softener resin and reducing its effectiveness.
Too much iron could damage your water softener, so we recommend buying a dedicated iron removal system if you have iron levels lower than 3 PPM.
Water softener pros & cons:
- The advantage of using a water softener for iron removal is that it removed dissolved iron and softens your water, giving you two benefits in one.
- However, a soft water system needs regular maintenance, including salt top-ups, to keep working properly, and high levels of iron in your water supply will damage the softening resin.
Oxidation Iron Removal Filters
The best method of removing high iron levels (5 PPM+) from your water supply is to use an oxidation iron removal filter.
In this unit, water flows into a tank containing a catalyst for oxidation (this could be an air pocket, a certain media, a certain chemical type, or a combination of several). The iron changes state and becomes oxidized, and is captured in a media bed.
When the media bed is saturated with iron and other oxidized minerals, the system will flush the minerals away with backwashing.
Oxidation can be used to remove ferrous or ferric iron, since it converts ferrous iron to a ferric form before removing it.
There are a few different media and chemicals that may be used in an oxidation iron filter, including aeration, ozone, chlorine, hydrogen peroxide, potassium permanganate, birm, and manganese greensand.
Let’s start by looking at the popular chemical-free method of oxidation:
An aeration and filtration system, otherwise known as an air injection iron filter, can remove high concentrations of ferric iron from well water.
Because this filter also converts ferrous iron into ferric iron, it’s a good option for anyone dealing with both types of iron in their well and water system.
An aeration iron filter uses a “nozzle and venturi” assembly that creates a vacuum, which draws air into the tank. This air forms an oxygen bubble at the top of the tank, which is regularly refreshed to enable proper iron oxidation.
Water passes through the oxygenated air bubble, then flows into a media or resin bed, such as birm or manganese greensand, which traps oxidized minerals. Iron-free water flows out of the system for whole-home use.
Aeration and filtration are capable of removing large quantities of iron, usually up to 30 PPM. These methods can also remove high levels of manganese and hydrogen sulfide.
Aeration & filtration pros & cons:
- The key benefit of aeration and filtration is that no chemicals are added to your water, so it retains its quality and you don’t have to use an additional filtration stage after treatment.
- However, the effectiveness of this water treatment depends on the amount of oxygen in the tank and the quality of the resin or media used, so results may vary.
Now let’s look at the different chemicals that may be used in an oxidation system:
Chlorine Oxidation + Filtration
A chlorine oxidizing system uses a feed pump to deliver a measured amount of chlorine – an effective chemical oxidizing agent – into water. The water is held in a tank to give the chlorine time to take effect. Around 20 minutes of contact time is typically required for chlorine to oxidize the iron in water.
Once the iron has precipitated out of the water, a GAC (granular activated carbon) filter is used to capture the iron and the chlorine, so water is iron-free and safe to drink.
Chlorine oxidation filters offer similar results to aeration water systems, but are less convenient, as you have to wait for the chlorine to take effect.
Chemical oxidation is another of the most effective iron-removal solutions, and can remove up to 20-30 PPM of iron.
Chlorine oxidation pros & cons:
- Chlorine is an effective oxidizer for water with iron levels of 8 PPM or less. An advantage of using chlorine for oxidation is that it’ll also disinfect your water.
- However, chlorine isn’t the best oxidizer, which is why water needs to spend time in a retention time to increase its contact time with the chemical. The additional filtration stage to remove the chlorine and oxidized iron increases the total upfront cost of this system.
Ozone treatment is another common chemical oxidation method, following chlorine.
Ozone actually oxidizes water more effectively than chlorine, but ozone systems typically use more electricity and are more expensive to operate.
The ozone treatment process works by exposing raw water to ozone, causing the iron and other minerals to oxidize. A GAC filter is used to filter out the iron precipitate and ozone/
Ozone treatment pros & cons:
- The biggest benefit of using ozone to remove iron is that it’s more effective than chlorine. It also costs less to run an ozone treatment system.
- However, the initial upfront cost of an ozone system is more expensive, and you’ll need to buy an oversized system to ensure it produces enough ozone to properly oxidize all the iron in your water.
Hydrogen peroxide injection systems are rapidly becoming one of the most popular choices for iron removal, for one simple reason: they’re highly reliable and effective.
Hydrogen peroxide, or H2O2, works better than oxygen to oxidize iron, and doesn’t produce as much iron sludge as other chemical methods.
No contact time is needed: a measured amount of H2O2 is simply injected into the water, which gets to work immediately.
Hydrogen peroxide pros & cons:
- Hydrogen peroxide is highly effective and doesn’t require a long contact time, so you don’t need to store water in a contact tank before it can be used.
- You’ll need to top up the hydrogen peroxide, so this method isn’t quite as hands-off as air injection. Plus, the upfront cost of this system is high.
Another chemical compound used in oxidation systems is potassium permanganate. This inorganic compound combines manganese oxide ore with potassium hydroxide and is commonly used alongside manganese greensand media.
Potassium permanganate offers an effective oxidation solution for water containing a high quantity of iron minerals and manganese. This type of oxidizer is usually effective at reducing up to 10 PPM of iron.
Potassium permanganate pros & cons:
- The combination of potassium permanganate and manganese greensand is ideal for treating iron contaminated water.
- However, this chemical, which is dyed purple for safety reasons, may linger in the manganese greensand bed, and may give your water a pinkish tinge.
You might also come across a number of iron removal systems that use polyphosphate as a chemical iron treatment method.
This chemical is a little different: it doesn’t oxidize or physically remove iron, but actually prevents oxidation by causing the iron to stabilize and disperse, preventing iron staining.
As with the other chemical treatments, polyphosphate is injected into the water in the treatment system.
Polyphosphate pros & cons:
- Because polyphosphate doesn’t oxidize or filter iron out of water, it requires fewer treatment stages and tends to be more affordable and less bulky.
- The biggest disadvantage of using polyphosphate treatment is that it won’t stop iron from precipitating in your water when you boil it. Plus, this treatment is only good at preventing the effects of low iron levels, around 3 PPM or less.
Finally, let’s look at the different media and resin types available in air injection iron filters:
Birm is made from a natural material, usually pumice, coated with manganese dioxide. As an insoluble catalyst, birm facilitates the reaction between iron and dissolved oxygen, enhancing the oxidation process. The birm then captures the oxidized iron particles and filters them out of the water.
There must be enough dissolved oxygen in water for birm’s iron removal media to work. Many birm systems require an air pump to increase the oxygen levels in water.
Birm filters can remove up to 10-15 PPM of iron in well water.
Birm media pros & cons:
- The biggest advantage of birm filters is that they require minimal maintenance when they’re used under the right conditions. The media should last 4-8 years with regular backwashing cycles.
- If you have manganese as well as iron, birm media isn’t the best solution – we recommend looking at manganese greensand instead.
Manganese greensand filter systems are made with manganese dioxide-coated beads or pellets. This media is capable of oxidizing and filtering iron: the manganese oxide coating releases oxygen, which oxidizes the iron present in the water, and the media bed traps these oxidized particles until they’re removed by backwashing.
During backwashing, potassium permanganate or chlorine is used to clean the media bed, preventing clogging.
A water pH of above 7.5 is required for a properly functioning manganese greensand filter. In optimal conditions, manganese greensand filters are also capable of removing between 10 and 15 PPM of iron from water.
Manganese greensand media pros & cons:
- Manganese greensand is lightweight and doesn’t use a lot of water for backwashing, and it’s an excellent option for iron and manganese removal.
- However, there are a few specific conditions that must be met for greensand to work properly, including a water pH of above 7.5 and no tannins in the water.
Katalox, Filox, & Pyrolox
There are several other media types that may be used in an oxidation system. Three media types made from manganese oxide are katalox, filox, and pyrolox.
These media work by instigating a reaction between oxygen in the water and the dissolved iron, forming ferric hydroxide.
Different media types of different iron removal abilities, but most media can remove around 15 PPM of iron.
Katalox, filox, & pyrolox media pros & cons:
- Many of these media types have a large surface area, meaning that they can offer higher filtration rates.
- The biggest issue with these media is that they’re very heavy, and a lot of water is needed for the backwashing process.
With a copper-zinc media, a KDF water filter produces an electrochemical reaction that converts harmful contaminants into non-harmful, or removable, forms.
This type of water filter is effective at removing iron in both soluble and insoluble forms, but is best for ferrous iron.
KDF oxidizing filters are more effective when water has a slower flow rate, giving it more contact time with the media.
Most KDF filters can remove between 4 and 6 PPM of iron. Again, it’s best looking at a dedicated iron filter if you’re dealing with a higher concentration of ferrous iron.
KDF media pros & cons:
- KDF is an effective water filtration method for low iron levels. Because KDF is typically used in a filter cartridge, it’s a better choice for people who prefer to change a filter rather than deal with chemical top-ups and backwashing.
- If your ferrous iron levels are particularly high, we don’t recommend KDF filters because high iron levels will clog or damage the filter.
Ferric Iron Treatment
To treat ferric, or insoluble, iron, you have the following whole-house treatment options available:
The iron filters that can convert ferrous iron to ferric iron can also be used to remove iron that’s already oxidized. These include birm, manganese greensand, KDF and air injection oxidation.
Sediment Cartridge Filters
Sediment water filter products remove suspended sediment in water, like dust, sand, and rust. You can use them to remove iron from well water in ferric form, which usually shows up as brownish-red flakes.
These filters use mechanical separation to trap iron particles in the filter media, allowing only water particles (which are smaller than the media pores) to pass through. The common pore size for a sediment filter for ferric iron removal is 5-10 microns.
Soluble ferrous iron can’t be removed from sediment filters, as it’s dissolved in water, so it’ll pass straight through the filtration system with the water particles.
Most sediment filters can remove an average of 6 PPM of iron. If your ferric iron levels are any higher than 8 PPM, a sediment filter isn’t the best choice.
Sediment filters pros & cons:
- Sediment filters physically trap iron and rust particles, so you should be able to tell the difference between your filtered and unfiltered water by its appearance and color.
- You might need several different filter stages with different micron sizes to trap rust and bacteria particles of various sizes. Plus, very high levels of ferric iron will clog the filter media quickly. If you have very large flecks of rust in your water, we recommend a spin-down sediment filter instead.
Bacterial Iron Treatment
Iron bacteria, or bacterial iron, is a particularly tricky contaminant. Many of the methods of iron removal are incapable of removing iron bacteria.
Instead, methods of physical removal, then shock chlorination or chemical disinfection, will be required. This is typically followed by chemical injection, which will kill bacteria and prevent iron bacteria formation in the long run.
👨🔧 It’s important to understand how to treat iron bacteria in well water if this is the problem you’re dealing with. We’ve shared the most effective ways to remove iron bacteria in this guide.