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Iron & Manganese Removal

by Mark Timmons September 06, 2009 48 Comments

People have struggled with iron (also called "rust") and manganese removal since the dawn of time. Adam complained to Eve that his new t-shirts were stained orangish-red (OK, I just made that up!). Removal of iron has been the topic of discussion between water treatment dealers for years ("my water softener removes iron better than any other softener, etc."). The fact of the matter is that iron CAN be removed using an ion-exchange salt-regenerated water softener, but usually, a water softener doesn't do it very long or very effectively. The best water softeners for removing iron are those that have twin softening tanks (one is always in service), which regenerate with soft water and fill the brine tank with soft water. If you have a water softener that removes ALL the iron, consider yourself as lucky as winning the lottery. Softeners work well to do just what they are supposed to do - soften the water by removing the calcium and magnesium, but iron (rust) is another animal and to remove it effectively, it usually has to be oxidized. Neither iron nor manganese in water presents a health hazard. However, their presence in water may cause taste, staining, and accumulation problems.

How to oxidize iron is the subject of this blog post. Because iron and manganese are chemically similar, they cause similar problems. Iron will cause reddish-brown staining of laundry, porcelain, dishes, utensils, and even glassware. Manganese acts in a similar way but causes a brownish-black stain. Soaps and detergents do not remove these stains, and the use of chlorine bleach and alkaline builders (such as sodium carbonate) can actually intensify the stains. Iron and manganese deposits will build up in pipelines, pressure tanks, water heaters, and water softeners. This reduces the available quantity and pressure of the water supply. Iron and manganese accumulations become an economic problem when water supply or softening equipment must be replaced. There are also associated increased energy costs, like pumping water through constricted pipes or heating water with heating rods coated with iron or manganese minerals. Most iron filtration systems operate on the principal of oxidizing the iron (oxidation) to convert it from a ferrous (dissolved or soluble) to a ferric or undissolved state. Once in the ferric state, iron can be filtered. Water filters are the most widely used equipment in removing iron. Its popularity comes from its versatility due to the various media products available and the process involved with each media. The most common reasons for filter failure are a lack of flow in backwash or a lack of frequency of regenerations. Low pH levels when using filters are another reason for unsatisfactory results.


For year, chlorine has been the oxidizer of choice. In addition to it's ability to oxidize iron, it also kills bacteria in the water. It does require a certain amount of contact time, so a drawback is that extra space is required for a retention tank (typically 24" x 72") or larger. Chlorine can be injected as a liquid before the pressure tank, or it can also be dropped down the well casing in the form of a pellet, using what is called a pellet chlorinator. This device is mounted on top of the well casing and is wired into the pump circuit, so that it runs when the well pump runs. You can calibrate it to drop pellets at whatever rate is needed to oxidize the iron at the source. Following injection of liquid chlorine or chlorine pellets, the chlorine and oxidized iron/sulfur needs to be removed by a back-washing carbon filter. It is an excellent idea to "oversize" the filters as chlorine combines with organics in the water to form trihalomethanes (THM"s) which are known carcinogens. Make sure your carbon filter is big enough to properly remove them. Water-Right, Inc. a company located in Appleton, Wisconsin has a very effective product called "The Sanitizer." The Sanitizer utilizes naturally silica zeolite, which is mined from the ground and is impervious to chlorine. During the brining cycle, two electrodes in the brine line generate large amounts of chlorine from the salt in the brine tank (NaCl is turned into Cl2). This is very effective at eradicating iron, manganese and even small amounts of sulfur.


Manganese greensand filters have generally been replaced with "Greensand Plus" media which is reported to be more effective at iron removal. Greensand is one of the oldest but proven oxidation technologies. Potassium permanganate, itself an oxidizer, is used to regenerate the greensand. In this application, potassium permanganate produces manganese dioxide on the surface of the mineral and — once the water comes in contact with it — any iron is immediately oxidized. The iron can be filtered and then cleaned away in the backwash cycle. Greensand is also effective with low levels of H2S (hydrogen sulfide) and manganese. Greensand Plus is a granular mineral with a manganese dioxide coating having the same ability as regular greensand. It is much lighter and requires less of a backwash rate than standard greensand. The main drawback is the potassium permanganate which is a harsh oxidizer and produces a vivid purple color if any of it is introduced into the water. The tank that holds the potassium permanganate is subject to overflow which leaves horrid purple (black) stains in its wake.


Injecting ozone into the water system is a very viable, albeit expensive, way to remove iron. Ozone is a powerful oxidizer and when used properly can be effective on large amounts of iron. Ozone is injected into water via a contact vessel as a pre-treatment to filtration. Ozone generators come in many designs and sizes and a full understanding of the process is necessary for success. Due to ozone's expense, it is usually applied on iron levels higher than normal filtration is known to handle effectively.


Hydrogen Peroxide (H2O2) is injected into the water ahead of a backwashing filter containing catalytic adsorptive carbon. The iron and manganese and sulfur are oxidized and the precipitate is trapped and later backwashed out, by the backwashing filter. H2O2 is composed of the elements of water - hydrogen and oxygen and is excellent at removing iron, manganese and sulfur. The only drawback is that you will have an annual hydrogen peroxide bill.


Oxygen in the air is an effective oxidizer and there are many ways to inject it into the water, including the use of "air pumps." A new development is the use of a valve that draws in a head of air and allows the iron to be fully oxidized before it goes through the media bed.

SPECIAL FILTERS (Birm, Filox, Pyrolox, Metal Ease, etc.)

Several companies make backwashing iron removal filters which remove iron utilizing special media with manganese dioxide being the key ingredient. Birm has the ability to remove iron and manganese and does not affect hydrogen sulfide. Like manganese dioxide, birm also uses dissolved oxygen as a catalyst and may require some type of pre-oxidation in cases where the dissolved oxygen content is too low to affect a maximum iron removal result. This technology is seldom the answer. Manganese dioxide is a naturally mined ore with the ability to remove iron, manganese, and hydrogen sulfide. The hydrogen sulfide capability exceeds that of either greensand or synthetic greensand and requires no chemicals to regenerate. It does, however, require adequate amounts of dissolved oxygen in the water as a catalyst and may require some type of pre-oxidation to achieve its maximum ability. Manganese dioxide is sold under the names of Filox, Pyrolox, Metal-Ease and Birm. Filox seems to be the best of the bunch.

KDF-85 Media

KDF-85 is a "Redox" media, which requires adequate dissolved oxygen to be effective, consists of two metals - 85 percent copper and 15 percent zinc. These two dissimilar metals create a small electrical field in the bed that will not allow bacterial growth in the media. This property earns redox the unique distinction of being effective on bacterial iron without the use of chlorine injection and being rated as bacteriostatic. Effective on removal of iron and hydrogen sulfide, able to reduce chlorine and heavy metals such as lead and mercury, redox is not effective with manganese. The biggest drawback for this media is its weight. Being almost twice as heavy as other minerals, it requires more than twice the backwash rate of other minerals.

More To Come

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January 29, 2018 Mark Timmons

We can help. I am not a fan of using chlorine in this application. I would recommend this: Step 1: Backwashing Sediment Filter: Step 2: Synergy Twin-Alternating Softener: Use iron out salt and Rust Out periodically and it will soften the water and remove the iron and manganese due to the 6.7 pH.

April 01, 2018 Mark Timmons

That water analysis is very incomplete. I would suggest a better one:

April 01, 2018 M L Matern

Our church has been designated as a public water supply by the State. We have a water treatment system in place is designed as follows: Raw water —> Ph Neutralization —> AIO Iron & Manganese removal —> Sediment Cartridge filter —> UV Sterilization —> Finish Water routine monitoring of PH averages around 7.11 until calcite media gets coated by manganese and requires replenishment. recent testing shows: Coliform = 0, Perchlorate = none, Conductivity = 240 umhos/cm, All secondary contaminants (except Iron and Manganese) are within state mandated limits, Iron and Manganese is our problem. I currently do not have test results for these in the Raw water, however the Finish water has been consistently Iron @ 4-7 mg/L and Manangese @ 1.2-1.6 mg/L. The state limit for iron is 0.3 mg/L (but they don’t seem too excited about it) and manganese is 0.05 mg/L (which the State is very upset about). Recently we discovered that our plumber had not been replacing (for at least 2 cycles over 1-2 years) the Fleck filter-head valve seals properly, causing some level of raw water to leak past the AIO filtration. That has now been remedied and we are awaiting results of the most recent testing to see how much of a difference that will make. Maybe it will make this question a mute point? However after reviewing older historical data for Iron and Manganese from this well it appears that we may never have tested within limits. I would like to know if the system we are using really is the best choice and perhaps we need to increase the filtration capacity (add a second AIO filter for instance) or maybe a different filter method is required for raw water with these levels?

April 01, 2018 Mark Timmons

I would keep the AIO, but as you can see, they do not do a lot. Here’s what will remove the iron and manganese the best: This is because it regenerates with soft water and fills the salt tank with soft water. Use Iron-Out Salt!

January 31, 2019 Brad

Hi Mark! I live in Reno NV and have some of the worst water out there. Low pH (3.2), Iron at 27 ppm, High Sulphates, and TDS around 2600. I have a very complex, multi-stage whole house RO system. I works pretty well, but I go through a set of 3 x RO membranes a year which usually runs around $1200. Someone stated that the Iron is clogging and reducing my membrane effectiveness. They recommended a “Chlorine pellet dispenser, a Twin-tank contact tank with pump that transfer water between the 2 Tanks”. They said this would precipitate out the iron in the contact tank & prevent further degradation of membranes. Does this sound like it could work? If so, where could I find these specific components? Names, nomenclatures, manufacturers? Thanks.

February 03, 2019 Mark Timmons

Brad, It would be very reckless of me to comment on your question, without more information. A Chlorine pellet dispenser, a Twin-tank contact tank with pump that transfer water between the 2 Tanks sounds like a big problem in itself. I would need more information about your water and existing system, but I seriously doubt that is a viable solution. First, I would need to see a detailed water test (something like this: If you don’t have it, you can order that one. We need to know “competing contaiminants” and other water parameters. We specialize in treating that kind of water, so YES, we can help you. I just need more information.

January 09, 2020 Becky Dixon

Hi, we have a well and after initial testing we added a heavy metal filter system with a UV light . After adding the 3 filters we retested our water. ( at the kitchen sink) We currently still have a high iron and manganese rating . Per our local health department everything else was considered ok. Our current iron is 0.58 mg/L Nd our manganese is 0.64 mg/L. In addition to filtering out water into the house we have a. Nikken filtration system for all our drinking and cooking . We would like to add an additional filter for the iron and manganese( my husband does not want a brine solution) Do you have any recommendations? * Also as of yesterday we replaced our hot water heater that was 23 years old . It was full of sediment so some of our issues may have been from that. Thank you !! Becky

January 15, 2020 Mark Timmons

Based upon the information given, I would recommend this:

March 11, 2020 Bill

Hi Mark. I’m new to we’ll water but test from Penn State came back at these levels. Coliform and E coli- none detected. Ph- 7.78. Total Dissolved Solids- 140. Total hardness as CaCO3- 131. Corrosivity/Scaling Index @25 degrees celcius- 0.24 Non-corrosive. Copper, running water- 0.02. Copper, first draw- 0.02. Iron- 0.10. Manganese- 0.239. Lead, running water- less than 0.003. Lead, first draw- less than 0.003. Calcium- 47.9. Magnesium- 2.8. The report states the sample failed the drinking water standard for Manganese. What do you suggest? Thanks in advance.

March 15, 2020 Mark Timmons

While your hardness isn’t high, there is enough to recommend removal with a water softener, and manganese is best removed at these levels by a softener as well. To do an effective job for many, many years, I would recommend our Synergy Water Softener, which has twin-tanks. This enables it to regenerate with soft water and fill the brine tank with soft water, which enhances the manganese removal. You should achieve near 100% removal.

March 15, 2020 Bill

Thank you

April 28, 2020 kawal singh

I used out filtermate potassium parmangante (PP) in my resin based water softner to clean the resin. Did PP ruin the water softener resin bed or not? Will it now be Ok to use normal Pro res care?

May 01, 2020 Mark Timmons

I have no idea if it did or didn’t, but we recommend using this in water softener resin beds:

May 18, 2020 Shannon

Hi, We have a flex 2510 backwashing system, I believe its called, when we firt installed it with filter ag plus. After 2 yrs we started seeing orange in toilets and such again. When we decided to change media to katalox light, recommended by filter seller. The inside parts of filter tank was covered in orange slime,I believe to be iron bacteria. After cleaning inside of filter tank and adding Katalox the system filtered great but short lived, maybe two months. Orange toilet again. So im thinking its building up inside the filter again,with the slime, perhaps. Should I do a chlorine well cleanse? Im thinking if i run chlorine through the filter maybe it will clean the slime. Any thoughts? Thx

May 18, 2020 Mark Timmons

What you are asking is like saying to the Doctor “I have a sharp pain in my stomach – tell me what I need.” Before a good doctor prescribes anything, he will run some tests… and that is what you need to do first. Here’s what you need to do: If the water doesn’t smell like rotten eggs, then do this too: Once we know EXACTLY what is in the water, then we can fix it.

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