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Last updated: February 27, 2026

How to Remove Manganese from Well Water

Affiliate disclosure: This page contains links to products. If you buy through our links, we may earn a commission at no extra cost to you. Our recommendations are based on research, not compensation. Test your water before choosing treatment, because source water varies by region and well.

Manganese treatment looks similar to iron treatment because both are dissolved metals that need to be oxidized before they can be filtered out. The right system depends on your manganese concentration, your iron level if you have both, and your water’s pH.

Get a lab test before you buy anything. Guessing at treatment without knowing your actual manganese level and water chemistry is how people spend money on the wrong system.

How Manganese Treatment Works

Dissolved manganese in well water exists as Mn2+, a positively charged ion in solution. You can’t filter it out with a simple sediment filter because it passes through filter media in its dissolved form. The first step is oxidation, which converts Mn2+ to MnO2, an insoluble particle. Once it’s a particle, you can filter it.

Different treatment approaches handle the oxidation step differently.

Oxidizing media (greensand, Birm, MnO2): These filter media have an oxidizing coating that reacts with dissolved manganese as water passes through. The media converts Mn2+ to MnO2 on contact, and the resulting particles are trapped in the filter bed. Greensand is the traditional choice. Birm works at higher pH values. Dedicated MnO2 media like Filox or Katalox are more aggressive and handle higher concentrations.

Air injection (aeration): An air injector injects a small pocket of air ahead of the filter tank. Dissolved manganese contacts the oxygen and oxidizes before reaching the filter media. The media then captures the particles. This approach works well when manganese levels are higher or when you also have iron above 3-5 mg/L.

Chemical oxidation (potassium permanganate): At high manganese concentrations, potassium permanganate is injected ahead of the filter. It’s a strong oxidizer that handles difficult water chemistry. This approach requires more maintenance and careful dosing, so it’s more often used in commercial or high-concentration residential situations.

Treatment Options by Concentration Level

Your manganese test result determines the right starting point.

Below 1 mg/L: A greensand or Birm filter handles this without aeration. If you also have iron below 5-6 mg/L, the same filter addresses both. Make sure your pH is above 6.8, because these media work poorly in acidic water. If your pH is low, address it first.

1 to 3 mg/L: MnO2 media (Filox, Katalox, or similar) is a better choice than basic greensand at this range. Adding air injection ahead of the filter improves performance and extends media life. This range is where cutting corners on media type tends to cause problems.

Above 3 mg/L: Air injection or potassium permanganate injection is needed before filtration. A whole-house system in this range involves two stages: oxidation first, then filtration. This is also the range where a water treatment professional’s input is worth the cost, because getting the sizing and chemistry right matters more.

Combined iron and manganese: The two often appear together, and most iron treatment systems address both. When sizing the system, add your iron and manganese levels together to get the combined dissolved metals load. The system needs to be rated for the combined total, not just each individually.

Point-of-Use vs. Whole-House

A whole-house filter addresses manganese at every tap, including laundry (where manganese staining is a real problem), showers, and washing. If you’re dealing with staining or you have children in the home who drink from multiple taps, whole-house treatment makes sense.

An under-sink RO filter handles drinking and cooking water. It won’t stop the staining on your laundry or fixtures, but it reduces manganese below detection at the kitchen tap. For households with an infant where the primary concern is formula water, an under-sink RO is the fastest path to treating the highest-priority exposure.

These aren’t mutually exclusive. Some households install whole-house oxidizing filtration for iron and staining control, plus an under-sink RO for drinking water to address manganese and other contaminants simultaneously. That’s a reasonable approach if your manganese level is elevated enough to warrant the health advisory concern.

See best iron filters for well water for whole-house oxidizing filter options that handle both iron and manganese.

The Softener Problem

Don’t use a water softener as your primary manganese treatment. Softeners remove dissolved manganese through ion exchange, but they’re not designed for it.

At manganese levels above about 0.5 mg/L, the resin becomes fouled with manganese oxide deposits. Once the resin is fouled, softener performance drops and the fouling is difficult to reverse. You end up with a degraded softener and still no reliable manganese treatment.

If you have a softener and also have manganese, the right approach is whole-house oxidizing filtration ahead of (before) the softener. The filter removes the manganese before it ever reaches the softener resin. The softener then handles hardness as it’s designed to do.

Maintenance

Oxidizing media filters require periodic backwashing. The backwash flushes captured MnO2 particles out of the filter bed and recharges the media. Most systems backwash automatically on a timer or flow meter trigger. Check that your system is actually backwashing by confirming the timer is set correctly after installation.

Greensand media needs occasional regeneration with a potassium permanganate solution to maintain its oxidizing capacity. Some newer MnO2 media doesn’t require chemical regeneration and recharges with air alone, which simplifies maintenance.

Plan to test your treated water once a year. A quick manganese test on post-filter water confirms the system is still working. If manganese appears in your treated water, the media may need replacement or the system may need rebalancing.

Media life depends on your water quality. At moderate manganese levels, greensand media typically lasts 5-10 years before replacement. MnO2 media often lasts longer. Check with your system manufacturer for specific guidance based on your water test results.

For lab testing resources, see best mail-in water tests.

Related pages: Manganese in Well Water | Manganese Health Effects | Best Iron Filters for Well Water

Sources

Frequently Asked Questions

What filter removes manganese from well water?
Oxidizing media filters (greensand, Birm, or MnO2 media) are the standard treatment for dissolved manganese in well water. They oxidize dissolved manganese and trap it as a solid. Air injection (aeration) systems also work and are preferred at higher concentrations. The right choice depends on your manganese level, iron level (often treated together), pH, and whether you have iron bacteria. A water test before buying is not optional here.
Does a water softener remove manganese?
A water softener removes dissolved manganese to some extent through ion exchange, similar to how it removes dissolved iron. But softeners aren't designed for manganese removal and will eventually foul the resin. At levels above about 0.5 mg/L, the softener will become contaminated with manganese oxide deposits. It's not the right tool for manganese above trace levels.
Does reverse osmosis remove manganese?
Yes. RO systems certified to NSF/ANSI 58 remove dissolved manganese effectively. RO is more practical as a point-of-use solution for drinking and cooking water than as a whole-house solution for manganese. If your concern is primarily infant or child exposure via drinking water, an under-sink RO handles the priority exposure pathway.
Can I treat iron and manganese at the same time?
Yes, and most iron treatment systems are designed to handle both simultaneously. Iron and manganese often appear together in well water, and the same oxidizing media that removes iron also removes manganese. Make sure the system you choose lists both iron and manganese removal in its specifications and is sized for your combined iron + manganese level.
What is the maximum manganese level an oxidizing filter can handle?
Most residential greensand or MnO2 media filters are rated for manganese up to about 3 mg/L. Above that, aeration or chemical oxidation (potassium permanganate injection) before the filter is needed. Your water test result should guide the sizing conversation. A water treatment professional can recommend the right approach for your specific level and other water chemistry factors.