How to Remove Iron from Well Water: 5 Methods Compared

There are five ways people try to get iron out of well water, and I get asked about every one of them. Only one takes dissolved iron out for good with nothing to keep buying: an air injection filter with Katalox Light, the media that traps the iron. Here is how the five compare, what each costs over 10 years, and when something cheaper is enough.

Iron Removal Methods: Side-by-Side Comparison

Only one of the five removes dissolved iron for good without something you have to keep buying. Here is how they line up.

10-Year Cost Comparison: Which Method Is Cheapest?

Over 10 years the air injection filter is the cheapest method that actually removes the iron, even counting one change of Katalox Light. Here is each method at today's prices.

The softener row only counts if your iron is low enough for a softener to handle, and if your water is hard you'd be buying that softener anyway. At a cartridge a month, the cartridge filter looks cheapest on the shelf and ends up the most expensive, and it still doesn't remove the dissolved iron.

People also ask me about the $500 iron filters sold online. In this video I go through those and the other cheap options people try first. My short answer is the one in the video: "it's like disposable diapers. Once one gets full, you gotta throw it away and get another one."

For every size and price, see the iron filter cost guide.

Method 1: Air Injection Oxidation Filter (Best Overall)

An air injection filter removes iron with air instead of chemicals, and it cleans itself. The valve draws air into the top of the tank. The air turns dissolved iron into particles, the Katalox Light traps them, and every day the valve backwashes the particles to the drain and draws a fresh pocket of air.

I don't recommend anything that adds chemicals to your water. As I put it in the video, "Any, any type of system that can impart chemicals into your water, that's a big no." This one doesn't need any.

How much iron it handles

Every size is rated for the same iron: up to 30 ppm, plus up to 15 ppm of manganese and 10 ppm of hydrogen sulfide (the rotten egg smell). Above 30 ppm, I put two 2.5 tanks one after the other.

Which size you need

The size comes from your household and how much water your well gives during the backwash, not from the iron number. Most homes buy the 2.5 cubic foot filter. It needs about 10 gallons per minute from the well to backwash, and the 1.5 cubic foot filter about 5. A well that gives less can still run the 2.5 with a longer backwash, which I set for you. If you're on a budget and can only afford one thing, I tell people the 1.5. The iron filter sizing guide goes through all four sizes.

What it needs from your house

Iron removal works best near pH 8. If your pH is lower, send me your test before you order, and I'll tell you whether an acid neutralizer goes in too, and in what order. The valve needs an outlet, and the backwash needs a floor drain, utility sink or standpipe. Drain tubing is not included; 1/2 inch tubing from any hardware store works.

The tank ships empty. The Katalox Light ships in separate bags and is poured in through the included fill funnel at install. We recommend a licensed plumber, and I support your plumber by phone.

What it takes to keep it running

There is no yearly maintenance. The Katalox Light lasts 6 to 8 years, depending on how much iron and water go through it, and then the media is replaced; the tank stays. That one media change is the only cost in the 10-year table beyond the filter itself.

The types of iron, testing and sizing are all in one place in the complete guide to iron filters for well water.

Method 2: Water Softener (Ion Exchange)

A softener only handles low levels of clear-water iron, and the iron shortens the life of the resin. In my video I put it at "low levels, say 1 to 3 parts per million." What I tell callers who are using a softener as the iron fix: "iron shortens the life of the resin. So eventually at, at some point it stops."

With iron in the water, the resin may last only 5 to 10 years. New resin is $295 a cubic foot, and a 48,000 grain softener holds 1.5 cubic feet. It also has to be clear-water iron: Penn State Extension says iron that has already turned to particles fouls the resin, so a softener is no help with red water.

A softener makes sense for iron when the level is low, the iron is the clear-water kind, and your water is hard anyway. When you need both, the iron filter goes first and the softener after it. More on that in can a water softener remove iron and iron filter vs water softener.

Method 3: Chlorine or Chemical Injection

Chemical injection works, but it is several pieces of equipment to keep up, and we don't sell it. A pump adds chlorine (bleach), hydrogen peroxide or potassium permanganate to the water. A holding tank gives the iron time to turn into particles, a filter catches them, and a carbon filter, if needed, takes out the chlorine taste. That list is from Penn State Extension's bulletin on iron and manganese.

The trouble I hear about is the upkeep, where people "just forget about it, and then the water goes bad again."

If you already have chlorine injection, it won't hurt the Katalox Light. As I told a caller who had one, "Chlorine doesn't hurt the performance of it. It actually can help it." A lot of people who add the Katalox Light end up removing the chlorine injection anyway. For iron bacteria I don't use chlorine injection either, and the Minnesota Department of Health does not usually recommend continuous chlorine injection into a well, because it may hide other bacteria and cause corrosion. The iron bacteria page covers what I use instead.

Method 4: Cartridge and Sediment Filters

A cartridge or spin-down filter catches rust particles, but dissolved iron passes right through it. About the filters you mount on the wall, I say it plainly in my video: "That doesn't work. That doesn't remove iron." Clear-water iron, the dissolved kind, is the type I see most, and a cartridge can't touch it.

What a cartridge does catch clogs it fast. As I tell callers, "if you have a lot of heavy iron and sediment ... in the water, it's gonna clog that filter pretty quick." A caller in Raleigh with only 0.3 ppm of iron changes his cartridge about once a month to keep a red ring off his toilets.

A spin-down filter, like the $145 Rusco we sell, is the same story: it's for dirt and sediment, not iron. Both have a real job in a well system. A 5 micron Big Blue ahead of the treatment keeps sand and dirt out of the valves, and a spin-down screen goes last, after the tanks. The correct order for well water treatment shows where each one goes.

Method 5: Shock Chlorination

Shocking a well kills bacteria for a while, but it does not take out any iron. Shocking disinfects the well with a strong chlorine solution; it doesn't filter anything, so the iron coming in from the ground water is still there once the bleach is flushed out.

It has a place. For iron bacteria, the Minnesota Department of Health says chlorine "may not always get rid of iron bacteria" and you may have to treat more than once. For a failed bacteria test, see remove coliform bacteria from well water. How to shock a well for iron bacteria, step by step, is on the iron bacteria page.

Other methods people ask me about

People ask me about four other methods, and each one has a catch.

Which Method Is Right for Your Situation?

Your test decides the method, so start with iron in ppm, pH and manganese. Then look at the water itself, because the three kinds of iron behave differently.

Here is the method I'd use for what your test shows:

The well test doesn't check for iron bacteria; the slime in the toilet tank is the sign. If manganese is your question, see how to test for manganese.

Have your water test in hand?

Text me your water test numbers

Send a photo of the lab report and I'll tell you which method fits, what size, and whether anything else goes in with it.

Text Aidan443-277-2204 Call800-460-5810Aidan

8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.

What buyers wrote after switching

These are verified purchases, newest first; two of them tried another method before this one. Reviewer names appear as the buyers wrote them.

Robert's old system is compared with ours in Iron Curtain vs Katalox Light.

Frequently asked questions