Iron Filter vs Water Softener (Do You Need Both?)
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A question I get a lot from people on a well with orange stains and hard water is this one: if I buy an iron filter, do I need a water softener too? If your water test shows both iron and hardness, the answer is yes. The iron filter takes out the iron; the softener takes out the hardness. Neither one does the other's job well, and the order you put them in matters.
Caller "So would I be able to keep the softener I got and then put one of your filters in front of it?"
Aidan "Yeah. Keep the softener you have and get a 1.5 cubic foot Fleck 2510 AiQ iron filter, and it takes out up to 30 parts per million of iron."
He called from Illinois in October with about 11 ppm of iron going through a softener a well company had put in: it was regenerating every other day and eating about 8 bags of salt a month. The softener wasn't the problem; asking it to take out that much iron was. This page is the long version of what I told him.
Quick Answer
Yes, you typically need both. If your well water has both iron and hardness, we strongly recommend running both systems at the same time. The iron filter goes first and the softener always goes last.
- The order. The iron filter raises the pH and adds hardness as it works, so the softener goes after it to take that out. See which goes first.
- A softener alone. It can take out low levels of clear-water iron, but iron shortens the life of its resin. See can a water softener remove iron.
- An iron filter alone. Fine on soft water, but it adds hardness: 3 grains can come out at 8 to 10. See when you need both.
- One combined tank. Okay for a couple who use little water; a family of four to six wants separate tanks. See all-in-one systems.
- Sizing. Size both from your household, pH, iron and hardness, plus how much water your well puts out. See how to size both.
An iron filter and softener bought together as a matched package run $3,995 to $5,495 from us.
What's in This Guide
What each tank takes out
An iron filter takes out iron; a softener takes out hardness. They are different tanks with different media inside, and each cleans itself a different way.
| Iron filter | Water softener | |
|---|---|---|
| Takes out | Iron (up to 30 ppm), manganese and the sulfur smell | Hardness, plus low levels of clear-water iron |
| Does not take out | Hardness. It adds hardness instead | More than a little iron, red-water iron or iron bacteria |
| Cleans itself by | Rinsing itself with water (backwashing) | Rinsing with salty water from its salt tank |
| What you add | Nothing. No salt, no annual maintenance | 40 lb bags of salt every 1 to 3 months |
| Needs at install | A drain line, a power outlet and enough well flow to backwash | A drain line, a power outlet and a line to its salt tank |
| Price from us | $2,495 to $3,495 across four iron filter sizes | $1,495 to $2,495 across four sizes of water softeners |
To run, the iron filter is the cheaper of the two, because our Katalox Light system does not need annual maintenance. The softener is the chore: you add salt every one to three months, which means picking up 40 lb bags at the store and carrying them home. A lot of my customers don't love that part, but it's what takes the hardness out.
When you need both tanks
If your test shows iron and about 7 or more grains of hardness, you need both an iron filter and a softener. Seven grains is where appliance manufacturers recommend a softener. Find your numbers below.
| If your test shows | What I put in |
|---|---|
| Iron and hardness of 7 grains or more | Both: the iron filter first, the softener second |
| A little iron and hard water | Still both. With 2 ppm of iron I put a dedicated iron filter in first, because iron weakens the softener resin over time |
| Iron, and hardness well under 7 grains | The iron filter. Retest the hardness after it, because the iron filter adds some |
| Hardness and no iron | A softener alone |
| Very high iron, over 30 ppm | Two iron filters in a row, then the softener |
| Acidic water (pH under 7) | Send me the test before you order; an acid neutralizer may go in too, and I'll tell you in what order |
| Slime in the toilet tank and an odor | That can be iron bacteria, which usually needs chlorine injection as well. See iron bacteria in well water |
Text Aidan your water test
Send a photo of the report and how many people live in the house. Aidan will tell you whether you need both and which sizes.
8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.The iron filter goes before the softener
From the well, the water goes through the pressure tank first, then a sediment filter if you have one, then the iron filter, and the softener goes last.
The iron filter raises the pH, and that adds hardness, so the softener has to come after it to take the hardness out. Taking the iron out first also keeps the softener working the way it should, on hardness alone.
Both valves backwash in the middle of the night, and both come set to 2 AM. Set them 2 hours apart, say 2 AM and 4 AM, so they never backwash at the same time. For every stage in order, including where an acid neutralizer or a UV light goes, see the correct order for well water treatment.
Who should install both tanks
What ships: both tanks empty, both control valves with the bypass valve pre-installed, the brine tank, a fill funnel, and the Katalox Light and softener resin in separate bags for loading at install. Drain tubing is not included.
I recommend having a plumber put it in, ideally one who has installed water treatment before: the tanks go in a set order, each valve needs its own drain line and its own outlet, and it takes about 3 to 4 hours for the two. I'm a phone call away for your plumber. If you'd rather do it yourself, text me with any questions. The steps are in how to install an iron filter and how to install a water softener.
Can a water softener remove iron?
A softener can take out a little iron, and only the clear-water kind. In my video on removing iron I put it this way: at "low levels, say 1 to 3 parts per million, a softener can remove iron from the water, but iron also shortens the life of the resin. So, further down the road, you're going to have to replace that resin, and it can be costly."
Clear-water iron is dissolved, so the water comes out of the tap clear. Red-water iron comes out of your faucet with a reddish tinge, and Penn State Extension says using a softener's resin bed as a filter for that kind of iron is generally not recommended, because it could damage the resin. Iron bacteria is a different problem with a different fix, covered in the FAQ below. The pH matters too: if the water is still acidic, a softener taking out iron works for about six months, and then it quits.
When iron fouls a softener, it's hard to backwash out. On a well that doesn't put out much water, the backwash can't lift the bed and spin it around in our Vortech tanks, so the softener regenerates over and over again and wastes water and salt. The Illinois caller at the top of this page had a softener doing exactly that, regenerating every other day. I've done this before when we did service: you take the unit outside, dump all the resin out and re-bed it with new resin, and that's not fun.
Our Katalox Light iron filter is designed to remove up to 30 parts per million of iron, which a water softener, in no way, shape, or form, can ever do. For the long answer, with each type of iron, see can a water softener remove iron.
Why the iron filter adds hardness
Our iron filter adds hardness while it takes out the iron. Its media, Katalox Light, raises the pH, because iron comes out best when the pH is close to 8, and it does that with a calcium-based material built into it. Watch Water, which makes Katalox Light, lists 5% hydrated lime (calcium hydroxide) in it.
That calcium is hardness. If you have 3 grains of hardness in your raw water now, it could go up to 8, 9 or 10 grains per gallon after the iron filter. A softener ahead of the iron filter would never see that added hardness, which is the other reason it goes last.
The pH jump can be bigger than you'd expect at first. Amy H., who bought two of our iron filters for very high iron, wrote, "The pH goes up to about 9 initially, but comes down eventually."
Is an all-in-one system a good idea?
For a family, I'd put in separate tanks, not one combined tank. An all-in-one puts two medias in one tank, one for iron and one for softening. In the video I say it's okay if you're, say, an elderly couple with minimal water usage. If you're a family of four to six, you want separate tanks: one for iron, one for softening, and separate tanks for any other problems in the water.
The All In One we sell today is a different kind of combined tank. It is one dual-chamber tank with carbon on top and softener resin below, $2,195. It softens the water and takes out low levels of iron the way any softener does, and the carbon is not an iron filter.
So on a well with iron, the All In One is still the softener in the line. With 2 ppm of iron or more, I put a dedicated iron filter in first.
How to size both tanks
Size both from four numbers: how many people live in the house, the pH, the iron in ppm and the hardness in grains. The pH should be at least neutral, and it's optimal closer to 8. When I size the softener, I count each part per million of iron as 5 grains of hardness per gallon.
The fifth number is your well. The iron filter needs enough water to backwash: about 5 gpm for the 1.5 cubic foot size, 7 to 8 for the 2.0, 10 for the 2.5 and 12 to 15 for the 3.5. The Illinois caller's well puts out 5 or 6 gallons a minute, maybe 7 on a good day, which is enough for the 1.5 and not the 2.5. If a well can't supply the flow, the backwash runs 20 minutes instead of the standard 14.
Inside what your well allows, I always tell a customer, "If you want low maintenance and not have to worry about it, bigger is better." Instead of a 1.5 cubic foot iron filter, step up to the 2.5, if your well can backwash it. As I put it in the video, you get "greater capacity, longer media life, and lower cost."
| Package | Fits | Price |
|---|---|---|
| Small (1.5 cu ft) iron filter + 48,000 grain softener | About 2 to 4 people, lower iron | $3,995 |
| Larger (2.5 cu ft) iron filter + 48,000 grain softener | 3 to 4 people on water up to about 15 grains | $4,395 |
| Larger (2.5 cu ft) iron filter + 64,000 grain softener | 5 or 6 people up to about 15 grains, or 3 or 4 people on harder water | $4,595 |
| Largest (3.5 cu ft) iron filter + 80,000 grain softener | 5 or 6 people on 16 to 30 grains | $5,495 |
For the detail on each tank, see the iron filter sizing guide and what size water softener you need.
Get all four numbers from one test
One certified lab test, mailed to you, run by an accredited lab, reports iron, manganese, hardness and pH, the numbers both tanks are sized from. If you already have a lab report, skip this.
53 contaminants, including bacteria, arsenic and lead.When one iron filter is not enough
Most of the time one iron filter is enough. But some of my customers have 50 parts per million of iron, and at levels that high I recommend two iron filters in a row: the first takes the brunt of it, and the second cleans it up.
Amy H. had over 20 ppm of ferrous iron and 7 ppm of ferric iron, along with manganese and some sulfur. She put in two 2.5 cubic foot iron filters and wrote that "now the tanks reduced the iron to literally zero!"
What I'd install on my own well
If I lived on a well with about 10 ppm of iron, this is what I'd put in my own house, in this order:
- A 20 inch Big Blue sediment filter to trap the small particles, $195
- The 2.5 cubic foot Katalox Light iron filter, $2,895
- A 64,000 grain Fleck 5600SXT softener, $2,195
- A 2.5 cubic foot non-backwashing carbon tank last, $1,695
- And probably a UV light, because I'm paranoid about bacteria
What buyers wrote
These are verified purchases of an iron filter and softener package.
| Buyer | Bought | What they wrote |
|---|---|---|
| Michael S., Aug 2026 Verified buyer | 1.5 cu ft iron filter and 48,000 grain softener | "Since installing the system, I've been extremely pleased with the results. The water quality improvement has been noticeable, and the system performs exactly as advertised." |
| Amy H., Apr 2023 Verified buyer | 2.5 cu ft iron filter and 64,000 grain softener | "We have 14ppm iron and this system has brought it down to almost zero." |
| Westley W., Mar 2020 Verified buyer | 1.5 cu ft iron filter and 48,000 grain softener | "Gave the values of water test, type and size of the well. Recommendation was accepted. Units were installed and run thru their cycles. Almost immediately water quality improved. MUCH better." |
Frequently asked questions
Do I need an iron filter for my water softener if my well water has 1.5 ppm of iron?
I'd put one in. A softener can take out that much clear-water iron, but iron shortens the life of the resin, and replacing resin is costly. For a caller in Indiana with 2 ppm of iron and 17 grains of hardness, I recommended a 1.5 cubic foot iron filter first and a 48,000 grain softener second.
Can you add an iron filter to a water softener well?
Yes. Keep the softener you have and put the iron filter ahead of it, after the pressure tank and any sediment filter. It needs its own drain line, an outlet and enough well flow to backwash. The steps are in how to install an iron filter.
How much does an iron filter for well water cost?
From us, $2,495 for the 1.5 cubic foot size up to $3,495 for the 3.5; the 2.5 is $2,895. A plumber typically charges about $800 and takes 2 to 3 hours to put one in. After that it needs no salt and no annual maintenance.
What is the best water softener for well water with iron and sulfur?
I wouldn't ask a softener to handle the iron and sulfur. Put a Katalox Light iron filter first: it is rated to take out up to 30 ppm of iron, 15 ppm of manganese and 10 ppm of hydrogen sulfide, the rotten egg smell. Then a Fleck 5600SXT softener sized for your household and hardness goes after it.
What are the signs that iron bacteria are present?
Iron bacteria builds up in your toilet tanks, floats to the top and gives off an odor. It usually requires chlorine injection and other filtration, not just an iron filter or a softener. See iron bacteria in well water.
Is it safe to drink well water that has iron in it?
The EPA lists iron under its secondary standards at 0.3 mg/L, for rusty color, sediment, a metallic taste and reddish or orange staining. It is a limit for stains and taste, not a health limit. For the full answer, see is iron in well water dangerous.
Aidan Walsh
Co-owner & Residential Water Treatment Specialist, Mid Atlantic WaterAidan Walsh has spent 32 years in residential water treatment, the first stretch of it installing and servicing well systems before Mid Atlantic Water became an online supplier. Mid Atlantic Water is a family company; every recommendation on this site is based on what actually failed in the field and what fixed it. If you have a question this page did not answer, call 800-460-5810 or text him at 443-277-2204.
Aidan answers calls and texts 8 AM to 5 PM Eastern, every day.Number copied. Text it from your phone: 443-277-2204.