Iron and Manganese in Well Water: Causes, Effects & Treatment
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Orange or rust-colored stains come from iron. Black or dark gray stains come from manganese. Both come out of the same rock as your well water moves through the ground, so a well that has one often has the other, and one air-injection filter takes out both for the whole house.
Manganese is the one people miss. It comes out of the tap clear, then turns black in the toilet bowl after the water sits for a few days, and a lot of people take it for mold or dirt. Unlike iron, manganese is also a health question, so it is worth knowing your number.
Quick Answer
Iron and manganese often appear together in well water. They dissolve from the same rock and soil formations as groundwater moves through your aquifer.
- How often they come together. In the wells my customers have had lab-tested, about 6 in 10 with iron over 0.3 ppm (parts per million, the same as mg/L on a lab report) also had manganese over 0.05 ppm. See why manganese so often comes with iron.
- Stains and taste. Iron leaves orange or rust stains and a metallic taste. Manganese leaves black or gray stains and a bitter metallic taste. See how to tell iron from manganese.
- EPA levels. The EPA's staining standards are 0.3 ppm for iron and 0.05 ppm for manganese. Manganese also has an EPA health advisory: 0.3 ppm for lifetime exposure, because of its effects on the nervous system. See is manganese in well water harmful.
- One filter for both. An air-injection filter with Katalox Light removes both in one tank. Every size we sell is rated for up to 30 ppm of iron and 15 ppm of manganese. It works best near pH 8. See how one filter removes manganese with iron.
- Test first. A certified lab test reports iron, manganese and pH from one sample. Ours is the $199 well water test kit.
What's in This Guide
Why manganese so often comes with iron
Iron and manganese are both in the rock your well water passes through, and acidic groundwater breaks both of them down into the water. Penn State Extension puts it the same way: the two often occur together in groundwater, and manganese usually shows up at much lower levels than iron.
Dissolved iron and manganese come out of the tap clear. That is clear-water iron, and manganese behaves the same way. Once the water meets air, the iron turns orange and the manganese turns black, which is why the stain shows up in the toilet bowl, where water sits for a few days.
The lab tests my customers send in show how often the two travel together. Of the wells where both numbers came back, about 6 in 10 with iron over 0.3 ppm also had manganese over 0.05 ppm (37 of 60). It runs the other way too: about 1 in 3 wells with manganese over 0.05 had iron under 0.3 (20 of 57). So an iron number alone does not tell you whether you have manganese.
How to tell iron from manganese
Iron leaves a reddish-brown or orange stain, and manganese leaves a grayish-black stain. If you see both colors, you most likely have both. A lot of people take the black for mold or dirt. As I put it to a caller in British Columbia, "manganese turns everything black."
| Iron | Manganese | |
|---|---|---|
| Stain color | Orange, rust or reddish brown | Black, grayish black or brownish black |
| Where you see it | Toilets, sinks, tubs and laundry | Toilet bowl, shower, tub, sink and laundry |
| Taste | Metallic | Bitter and metallic |
| EPA staining standard | 0.3 ppm | 0.05 ppm |
Hardware-store test strips are fairly accurate, but for an exact number, use a certified lab and ask for manganese by name, along with pH, iron, hardness and bacteria. For how to take the sample and read the result, see how to test for manganese. To get the orange marks off your fixtures, see iron stains.
Find out if you have manganese
One certified lab test, mailed to you, run by an accredited lab, reports iron, manganese, pH and hardness from one sample. If you already have a lab report, skip this.
53 contaminants, including bacteria, from one sample.Is manganese in well water harmful?
Iron stains but is not a health concern at the levels wells carry; manganese can be both. The EPA's 0.3 ppm for iron and 0.05 ppm for manganese are both staining and taste standards. The EPA's 2004 health advisory for manganese is 0.3 mg/L (0.3 ppm) for lifetime exposure and 1 mg/L for one to ten days; for infants under 6 months, the EPA says to use 0.3 mg/L even short term. Minnesota's health department goes lower for babies: 0.1 ppm if a baby drinks the tap water or formula made with it.
| Manganese on your report | What the number means |
|---|---|
| 0.05 ppm | EPA staining standard. Black stains start here. |
| 0.1 ppm | Minnesota's safe level for a baby's water or formula. |
| 0.3 ppm | EPA lifetime health advisory. Also the EPA's level for babies under 6 months, even short term. |
| 1 ppm | EPA health advisory for one to ten days. |
Of 308 wells my customers have had lab-tested, about 1 in 4 had manganese over 0.05 ppm, and about 1 in 13 were over the 0.3 lifetime advisory (24 wells). Iron is a different story; see is iron in well water dangerous.
Send me your lab report
Text me a photo of the report. I'll tell you whether the manganese needs treating, which size fits your house, and whether your pH calls for a neutralizer too.
A real person, not a call center.How one filter removes manganese with iron
An air-injection filter with Katalox Light removes iron and manganese in the same tank. Manganese is not harder to remove than iron. If you have 10 ppm of iron and 5 ppm of manganese, we use the same system as for iron alone.
The water comes into the top of the tank through a pocket of air. The air turns the dissolved iron and manganese into solid specks, and the Katalox Light (the filter media inside the tank) catches them. We tried the air pocket with Katalox Light about 15 years ago, and it worked so much better that it became the iron filter we recommend to all our customers. It is almost like getting two filters in one.
Every day or two, the valve backwashes: water runs up through the media, rinses what it caught down the drain, and the valve draws in a fresh air pocket. It ships set to backwash every day, and that can be set to less. There are no chemicals to buy and no yearly maintenance; every 6 to 8 years the tank is cleaned out and re-bedded with new Katalox Light.
Every size we sell is rated for up to 30 ppm of iron, 15 ppm of manganese and 10 ppm of hydrogen sulfide (the rotten egg smell). Above 30 ppm of iron, I put two 2.5 cubic foot tanks in a row.
What ships: the Vortech tank (empty), the Fleck 2510AIO control valve with the bypass valve included, and the Katalox Light in separate bags, poured into the tank through the included fill funnel at install. Drain tubing is not included; your plumber sizes it for the backwash. I recommend a licensed plumber for the install, and I support your plumber by phone at 800-460-5810.
"I have well water with over 20 ppm ferrous and 7 ppm of ferric iron, along with manganese and some sulfur. I was rejected by local water companies saying they could not help me with my high iron issues. I purchased two Fleck 2.5 cu. ft. 2510AIO Iron Filter tanks with Katalox-Light media and air injection from Mid-Atlantic Water. ... now the tanks reduced the iron to literally zero!"
Amy H., October 2024 Verified buyerAmy's review is from a verified purchase on our site.
In the video I give the 2.5 cubic foot price as $2,195 shipped. It is $2,495 today.
Why pH matters for manganese
For the best iron and manganese removal, you want a pH near 8. The filter itself helps raise the pH, but when the pH is low I recommend a neutralizer as well. If your pH is low, an acid neutralizer goes in too, and I set its place from your test, so send me the report before you order.
What does not work for manganese
A softener, a hardware-store cartridge or chemical injection can each handle some iron or manganese, but none of them is what I recommend once the levels climb.
| What people try | What happens with iron and manganese |
|---|---|
| Water softener | Removes low levels. Once you get to 2 to 4 ppm or more, you need a filter made for iron and manganese. Specks of iron or manganese foul the softener resin. More in can a water softener remove iron. |
| 5 micron cartridge from the hardware store | Clogs over time. You keep replacing it, and the problem stays. |
| Chemical injection | Means mixing chemicals in a tank in the basement every 30 days. I don't want to put chemicals into anybody's water. |
| Birm filter | Works at low levels when the pH is balanced right. |
| Greensand filter | Needs potassium permanganate, a purple chemical, to stay clean. Most people have moved to Katalox Light. |
For the full side-by-side, with what each method costs over 10 years, see how to remove iron from well water.
Which size filter fits your home
Every size handles the same 30 ppm of iron and 15 ppm of manganese. The size depends on how many people use the water and how much water your well can deliver. The backwash needs a steady flow from the well, measured in gallons per minute.
| Filter size | Household | Well flow needed for cleaning | Price today |
|---|---|---|---|
| 1.5 cubic foot (smallest) | 2 to 4 people, lower iron levels | About 5 gallons a minute | $2,095 |
| 2.0 cubic foot | More flow when several taps run at once | About 7 to 8 gallons a minute | $2,295 |
| 2.5 cubic foot (most popular) | 4 to 10 people, or 4 to 5 bathrooms | About 10 gallons a minute | $2,495 |
| 3.5 cubic foot (largest) | 6 or more bathrooms, or irrigation off the well | About 12 to 15 gallons a minute | $3,295 |
The 2.5 is the size we ship most. If you are between sizes, send me your test, how many people live in the house and your well's flow, and I'll size it.
What order the equipment goes in
The iron filter goes before the softener. That way the iron and manganese are out before the water reaches the softener resin. If I had iron and manganese in my own well, this is what I would put in:
- The 2.5 cubic foot air-injection filter with Katalox Light.
- A 64,000 grain Fleck softener for the hardness.
- A carbon filter last in line, to polish the water for the whole house.
I would also add a Viqua VH410 UV light to make sure the water is free of bacteria. If your pH is low, an acid neutralizer goes in too, and I set its place from your test. We sell the filter and softener together as iron filter and softener packages.
Frequently asked questions
Can you shower in water high in manganese?
Yes. Minnesota's health department says water above its manganese guidance level can be harmful to drink, but taking a bath or a shower in it is not. Massachusetts says the same about bathing a baby: manganese is poorly absorbed through the skin. It will still stain the tub and shower black.
What are the side effects of manganese in drinking water?
Minnesota's health department says children and adults who drink water high in manganese for a long time may have problems with memory, attention and motor skills, and that babies may develop learning and behavior problems. Above 0.05 ppm, it also leaves black stains and a bitter metallic taste.
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.