How To Treat Iron, Manganese & Odors Well Water

Iron is one of the earth's most plentiful resources, making up at least five percent of the earth's crust. In well water iron is usually found in a dissolved state and may appear clear when first drawn from the tap.

The maximum amount recommended in water is 0.3 mg/L which is same as saying 0.3 Parts Per Million or PPM. When the level of iron in water exceeds the 0.3 mg/l limit, the water may have a red, brown, or yellow color and stain laundry and fixtures. The water may also have a metallic taste and an offensive odor. Water system piping and fixtures can become restricted or clogged, and appliances such as water heaters, dishwashers and washing machines plugged with rust and sediment.

Iron gives water a disagreeable metallic taste. When the iron combines with tea, coffee and other beverages, it produces an inky, black appearance and a rusty, bad taste.

There are four main types of iron or conditions in which iron is found in well water:

  • • Soluble "Clear Water" Iron
  • • Insoluble Oxidized "Red Water" Iron
  • • Organic Iron
  • • Iron Bacteria

Questions to Ask When Choosing an Iron Filter:

1. What type of iron do I have in my water system?
2. What is the flow rate I have available, to backwash the iron filter I choose?
3. Do I have manganese, hydrogen sulfide odor, iron bacteria or tannin in my water?
4. What is the pH (acid or alkaline nature) of my water?
5. According to the water test results, will the water treatment unit remove the total iron concentration?

Test Your Water

If there is an iron problem with the water supply, the first step is to determine the source. The source of iron may be from the corrosion of iron or steel pipes or other components of the plumbing system where the acidity of the water, measured as pH, is below 6.8.

A laboratory analysis of water to determine the extent of the iron problem and possible treatment solutions should begin with tests for iron, iron bacteria, pH, manganese, tannins, hardness, and total dissolved solids. Take the sample as close to the well as possible.

It should always include a pH test, which indicates if the water is acidic or alkaline. With these results, you can identify if you need any type of water treatment, and what type of system to select, based on your water chemistry. Avoid in-home water testing by water softener sales people during sales demonstrations.

For health‐related issues at a minimum include a test for total coliform, e-coli (fecal coliform). If infants and children will be drinking the water, a complete general, mineral, metals and bacteriological test is recommend.

If the source of water is a public water system and you experience iron-related problems, it is important to contact a utility official to determine whether the red water is from the public system or from the home's plumbing or piping.

Check For Odors in Well Water & Water Heater

Run a hose bib or tap as close to the well as possible and fill a 5-gallon bucket or other container and notice if there are odors. If you smell a "rotten-egg" odor, this is hydrogen sulfide gas. If water smells like oil or asphalt this can be from manganese. If water smells like cucumber or sewage this is usually a result of iron and/or sulfur bacteria.

Run the water hot water from each tap and notice if there is an odor in the hot water, that is not in the cold water. This indicates a problem with the water heater. Iron and sulfur bacteria can interact with the anode rod in water heaters, resulting in hydrogen sulfide gas only in the hot water. Changing the anode rod to an aluminum rod can often solve this problem.

It is recommended that you drain your water heater at least once per year. This will flush out sediment that may accumulate in the bottom and give you an idea of the sediment type and color , if any, are present.

Perform a "Toilet Tank Inspection"

Unless your toilet tank is new or has recently been cleaned your toilet flush tank can be a wealth of useful water quality information! Simply lift the cover and look in. If you see slimy rusty deposits on the sides of the tank, and frothy bubbles in the tank water, this is a good indication of iron bacteria.


Water heaters can accumulate rust and sludge. Iron and sulfur bacteria can create sulfur odors in water heaters.

Symptom Cause Solution
White scale on float Calcium hardness Water softener
White scale on float Total dissolved solids Reverse osmosis
Tank sides are white, but black, rust or sand is laying on the bottom Decaying galvanized pipes Replace pipes; correct corrosiveness of water
Sand, rust or sediment in well water Sediment and/or iron filter
Blue Stains Acidic (low pH) water Calcite neutralizer or soda ash feeder
Rust Stains Iron Iron filter (Birm, MangOX, Greensand, Pyrolox)
Furry, stringy red growths Iron (and/or other) bacteria Chlorination, aeration, ozone injection, hydrogen peroxide, followed by filtration
Furry, stringy gray or black growths Sulfur (or other) bacteria Chlorination, aeration, ozone injection, hydrogen peroxide, followed by filtration
Frothy, with bubbles Iron bacteria Chlorination, aeration, ozone injection, hydrogen peroxide, followed by filtration
Brown stains Iron And/or Manganese Iron filter that removes manganese (MangOX, Greensand, Pyrolox)
Black Stains Iron And/or Manganese Iron filter that removes manganese (MangOX, Greensand, Pyrolox)
Ferric Sulfide (black rust) Iron filter (Birm, MangOX, Greensand, Pyrolox)
Pink Stains Airborne bacteria Not water quality related; Clean with chlorine bleach

Determine Your Well Pump Flow Rate

Your well pump can pump water up to a certain maximum flow rate, in gallons per minute. For example say you could fill a 5 gallon bucket in 1 minute. This is a flow rate of 5 gallons per minute or 5 GPM. If the water filled up a 5 gallon bucket in 30 seconds, the flow rate would 10 GPM. Knowing how many gallons per minute your water system can pump is critical to picking the right type of water treatment system, and it is easy to determine.

This method works for most well pumps. If your pump turns on at one pressure (typically 30 or 40 PSI) and off at a higher pressure (usually 50 or 60 PSI) this method will work for you.

It is easy! All you need is a 1 or 5 gallon bucket and a watch or clock. It takes just a few minutes:
1. Open any hose bib or faucet until pump turns on.
2. Close hose bib or faucet and let pump fill up pressure tank until it turns off.
3. Using a 1 or 5 gal. bucket, open faucet, collect and measure all water discharged until pump turns on.
4. When pump turns on, immediately close faucet and start timing pump cycle*
5. When pump turns off, record pump cycle time to refill pressure tank in seconds.
6. Divide the number of gallons collected in Step 3 by the number of seconds in Step 5.
7. Multiply the answer from Step 6 by 60.
8. The answer in Step 7 is the average pumping capacity of the pump in gallons per minute (GPM).

Pressure Tank with Submersible Well

How It Works: Submersible pump in well (1) is controlled by pressure switch (2). When pressure in pressure tank (3) drop below a preset level (typically 40 to 60 PSI) the pressure switch turns on well pump. Well pump continues to run until pressure in pressure tank builds up, and pressure switch reaches maximum pressure setting. The pressure tank contains a precharged air bag to moderate pressure in the piping system.
1 Well pump submerged in water
2 Well head with sanitary seal
3 Check valve (may be submerged in well and not visible)
4 Pressure switch
5 Pressure gauge
6 Pressure tank

Understanding the 4 Types of Common Problems and Solutions

The 4 Types of Iron Problems Treatment Recommendations:
Clear Water Iron
Water with clear water iron looks clear at first, and then develops color or rust after being exposed to air or other oxidants such as chlorine. Clear water is either removed as clear water iron, or oxidized to a particle form (rust) that can then be filtered out.
Clear Water Iron Treatment

Softener with Fine Mesh Resin

Greensand , MangOX or Birm Iron Filters
Red Water Iron
If all the iron in the water is found as red water iron, then a cartridge type filter, or a backwashing sand filter can remove it. However it is more common that even though the water contains red water iron, it also contains some clear water iron as well.
Red Water Iron Treatment

Greensand , MangOX or Birm Iron Filters

Filter cartridge system
Organic Iron
Organic iron and tannins present special water treatment challenges. Tannins are natural organics produced by vegetation which stain water a tea-color. Organic iron is a compound formed from an organic acid such as tannin or humic acids and iron. Organic iron and tannins can occur in very shallow wells, or wells being affected by surface water.
Organic Iron Treatment

Chlorine, Ozone or Hydrogen Peroxide treatment followed by activated carbon, and Greensand or MangOX Iron Filters

Tannin Filter System
Bacterial Iron
Iron bacteria are organisms that consume iron to survive and, in the process, produce deposits of iron, and a red or brown slime called a "biofilm." The organisms are not harmful to humans, but can make an iron problem much worse. Indications of iron bacteria include a red or yellow color to the water, slime on the inner walls of the toilet tank, and/or odors that resemble fuel oil, cucumber or sewage. These organisms naturally occur in shallow soils and groundwater, and they may be introduced into a well or water system when it is constructed or repaired.
Bacterial Iron Treatment

Chlorine, Ozone or Hydrogen Peroxide treatment followed by activated carbon, and Greensand , MangOX or Birm Iron Filters

Periodic Well Chlorination and Greensand or MangOX Iron filter.

Iron Treatment Methods and Considerations

Check for Pipe Corrosion and Scale Build-up

Unless your home is new, it is important to check for pipe corrosion scale build-up in the piping. Fortunately this is not difficult to do by using one of the following methods:

  • • Check for signs of blue stains in fixtures, blue stains in toilet tanks, which can indicate copper corrosion, and/or test water for copper.
  • • If you have galvanized iron pipe, look for signs of rust and rustcolored scale in the toilet flush tank.
  • • If possible, inspect the exterior of pipes and valves, to see if you see any signs of pinhole leaks or corrosion by-products which can be crusty, bluish, white or salty looking or rusty. If you are having any plumbing work done on your house, inspect any sections of the pipes that have been cut to see if there is any scale build-up or signs of corrosion.

Identify Pipe Sizes

It is useful to know the size of your incoming pipes. For instance, sayyou decide you want to in stall calcite neutralizer for your house. They come in different pipe sizes, such as 3/4" pipe, 1" pipe etc. Generally, you want to make certain you get a system that will not restrict the water flow or pressure, so if you have a 1" pipe, you would want a calcite neutralizer that has 1" pipe connectors. Knowing what size piping you have solves this problem.

It is easy to check the size of your pipes. First, check on the pipe itself, often it will be labeled or written on the side. If not, the string method which measures the circumference is probably the best way to determine your pipe size. Circumference is the distance it takes to go around the pipe once.

Remove any insulation from the pipe. Using a piece of string about 6" long (or a cloth tape measure) wrap the string around the pipe once and measure to the nearest 1/8 of an inch. Once you have found the circumference, use the chart below to find your pipe or tube size.

Oxidizing Iron Filters That Also Remove H2S

These iron filters oxidize the dissolved ferrous iron in water to an insoluble particle and trap the iron (rust) in the iron filter media. Some also remove hydrogen sulfide gas along with the iron. A periodic backwash cleans out the rust and flushes the filter media clean. Various types of iron filter media are available including Birm, Greensand, MangOX, Filox©, & Pyrolox©.

Oxidizing iron filters use either air, chlorine potassium permanganate, hydrogen peroxide or ozone to aid the filter media in oxidizing the iron. Note that Birm and Greensand are media that are coated with manganese dioxide, whereas Filox©, MangOX©, and Pyrolox© are all solid manganese dioxide media which perform similar to each other. Catalytic carbon is used with hydrogen peroxide and is the only media not containing manganese dioxide.

Pipe Circumference to
Pipe Size Chart

Copper Pipe or PEX tubing
2.75" (70mm) = 3/4" pipe
3.53" (90mm) = 1" pipe
4.32" (110mm) = 1 1/4" pipe
5.10" (130mm) = 1 1/2" pipe

Steel Pipe or PVC Plastic Pipe
3.25" (83mm) = 3/4" pipe
4.00"(102mm) = 1" pipe
5.00"(127mm) = 1 1/4" pipe
6.00"(152mm) = 1 1/2" pipe

Flexible Polyethylene Pipe
2.96-3.33" (75-85mm) = 3/4" pipe
3.74-4.24" (95-108mm) = 1" pipe
4.90-5.57" (124-141mm) = 1 1/4" pipe
5.70-6.28" (145-160mm) = 1 1/2" pipe


Air Injector Birm Iron filter


Greensand Iron Filter

Comparison of Oxidizing Iron Filters

* Backwash per square foot refers to the Gallons Per Minute required to backwash one square foot of the media. As an example, a 14" diameter tank has approximately a square foot surface area of 1 square foot. A 10" diameter tank has a square feet area of 0.5 square foot. So a 1.5 cubic foot Birm iron filter in a 10" x 54" tank would require 5 gallons per minute for backwash, whereas a MangOX filter would require a backwash flow rate of 8 to 12 GPM.

Birm and Birm Blend Iron Filters

Use Venturi-type air injectors to inject air

Birm is a trademark name of the Clack Corp and uses a type of granular filter media called "Birm". It is manufactured from a type of natural pumice mineral coated with manganese dioxide. As the water flows through the filter tank containing Birm media, a reaction occurs where the dissolved oxygen and the dissolved ferrous iron compounds form an insoluble ferric hydroxide. In plain English, as water containing iron flows through the media, if there is enough oxygen in the water, the Birm causes the iron to form rust, or solid iron particles. After these rust particles get trapped in the filter media, once or twice a week they are automatically backwashed out to drain, and the filter media is ready to filter again.

Birm is cheaper than other iron filter media such as Filox or MangOX, but it has several limitations. It does not remove manganese or hydrogen sulfide gas which are often found in well water containing iron. It cannot be used if the water is chlorinated, and it is quickly fouled by iron bacteria.

In most cases, Birm requires an air injector system to be able to work effectively. Birm will not work well if the pH is less than 6.9 – 7.0. Birm media generally needs to be changed every 3 – 4 years for most residential applications.

Birm is sometimmes blended with other media such as FilterAg, Chemsorb, Calcite and/or Corosex. The FilterAg or Chemsorb media help remove sediment. If the pH is less than 7.0, Calcite (a type of natural calcium media) and/or Corosex (magnesium) is added to the media to raise the pH up to neutral (7.0—7.4) range.


Air Injector + Birm‐Blend Iron Filter ("Terminator" brand)


• Removes Ferrous & Ferric Iron
• Does not remove manganese
• Not recommended for hydrogen sulfide "rotten-egg" odor
• Not recommended when iron bacteria is present
• Untreated water cannot have chlorine, tannin, or oil in it
• Lighter than other iron filters, works on well with lower flow rates

Typical installation of a air-injecting venturi-type Birm-Blend iron filter system:

How It Works: An 1" NPT pipe size air-injector is installed after the pump before the well pressure tank. When the well pump runs, water flows past the air injector and air is drawn into the water.

The water flows through the airvent tank where excess air is released before flowing through the iron filter tank. Some pressure drop will occur through the air injector, but if your well can produce at least 8 gallons per minute at 30 PSI then the pressure loss is usually not noticeable.

Birm Blend Air Compressor Systems

This type of iron filter uses a compressor to inject air into the water. This is a substantial improvement over the venturi-type air injector, because a much larger volume of air is injected.

This is more effective at eliminating sulfur odors and oxidizing higher levels of iron without the use of chemical oxidizers such as chlorine.

There is less pressure drop after the system with this type of iron filter because it does not rely on a venturi type air injector. Unlike air-injectors which can be clogged and need to be cleaned periodically, the air compressor produces a reliable and large volume of air to oxidize iron without chemicals oxidizers.

One result of the air compressor is that the water itself does become saturated with tiny air bubbles. Often when first drawing the water in a glass, the water may appear white, but it instantly clears as the air leaves the water.

• Removes Ferrous & Ferric Iron
• Does not remove manganese
• Not recommended for hydrogen sulfide "rotten-egg" odor
• Not recommended when iron bacteria is present
• Untreated water cannot have chlorine, tannin, or oil in it
• Lighter than other iron filters, works on well with lower flow rates

Typical installation air-injecting compressor-type Birm-Blend iron filter system:

How It Works: The compressor injects the air in a special type of airvent tank which allows some minutes of contact time for the oxygen to dissolve in the water, and also allow for venting of excess air and gasses.

After the water is aerated the Birm iron filter removes the oxidized iron, periodically flushing it automatically out to drain.

If the pH is less than 6.8 a Birm Blend filter using a combination of calcite and Birm can be used in the same tank. For levels less than 6.0 a separate neutralizer tank or a soda ash feeder is used.

Greensand Iron Filters

Uses potassium permanganate or chlorine bleach to kill odors and filter iron, manganese, and sulfide residue

Greensand filter media has a special coating of manganese dioxide, which oxidizes iron, manganese and iron in water, upon contact with the filter media.

Greensand is not affected by chlorination and works over a wider pH range. Greensand iron filters remove manganese and hydrogen sulfide.

To provide the oxidizing power to precipitate iron and manganese the iron filter is automatically cleaned and restored with potassium permanganate (a purple liquid) during each backwash cycle. As an alternative to using potassium permanganate powder, a chlorine injector pump is used ahead of the greensand-plus filter to regenerate the filter media. Greensand media generally needs to be replaced every 4 to 6 years.

For treating water with both hydrogen sulfide "rotten-egg" odor in it, and/or iron bacteria, it is best to chlorinate the water prior the greensand filter. The injection of chlorine substantially increases the effectiveness of the greensand media, and allows it to work without the use of potassium permanganate and remove higher levels of iron and manganese.


• Removes Ferrous & Ferric Iron
• Removes manganese
• Removes low levels of hydrogen sulfide "rotten-egg" odor
• Not affected by iron bacteria
• Works with chlorinated water.

What is "Potassium Permanganate"? Potassium Permanganate (KMnO4) is a purpleblack powder and powerful oxidizer. It is used with greensand iron filters to regenerate , clean and restore the oxidizing capability of the greensand iron filter media.

How it Works: Water flows in from the top down through the Greensand Media, removing iron, manganese and sediment., Filtered water flows down to the distributor screen, up the distributor tube, and out to the household piping. Once or twice a week, the Fleck 7000-SXT control valve timer starts a backwash and rinse, called a 'regeneration' cycle. This typically occurs in the middle of the night and is completely automatic.

During the regeneration cycle, the Greensand media is first backwashed thoroughly. During the backwash, water flows down the distributor tube and up through the Greensand media and out to drain, flushing out the accumulated iron and manganese and sediment.

After the backwash, some permanganate solution is sucked out of the permanganate tank, and the greensand is rinsed and regenerated restoring the exhausted media to a fresh state where it can continue to remove iron and manganese. The permanganate solution is rinsed out in two rinse cycles, and more water fills the permanganate tank and makes more permanganate solution from the permanganate powder that is in the permanganate tank.

Eventually the powder runs out, and fresh permanganate powder is added to the tank, typically once every 3—4 months.

Manganese Dioxide Filters (MangOX©, Filox©, Pyrolox©) Batch Regeneration Type

Unlike Birm and Greensand which are coated with a manganese oxide coating, these types of iron filters use a natural mined solid manganese oxide ore in a relatively pure form.

The iron filters utilize an oxidation-reduction reaction and filtraation process similar to Greensand, but at a much higher level of performance. MangOX for example contains greater than 85% manganese dioxide whereas Greensand contains around 1%. MangOX and other solid manganese dioxide media are very heavy and require a strong backwash flow rate to lift and clean the solid manganese dioxide mineral filter media.

An optional solution tank that contains chlorine bleach or hydrogen peroxide automatically cleans and restores the media in a process known as a "batch regeneration", as opposed to continuous regeneration where chlorine is fed into the water continuously ahead of the filter.

These filters are automatically backwashed every 1 to 3 days to keep the heavy media from fouling. The MangOX media out performs Greensand and Birm due to the purity of its particles combined with the superior oxidation, filtration capacity, and durability.

MangOX often lasts for 10 years or more, especially when used with a chlorine, peroxide or ozone feed. It is the highest performing iron filter media is works great with chlorinated water, or regenerated intermittently with chlorine or peroxide.

• Removes Ferrous & Ferric Iron
• Removes manganese
• Removes low levels of hydrogen sulfide "rotten-egg" odor
• Not affected by iron bacteria
• Works with chlorinated water.

How it Works: Water flows in from the top down through the MangOX Plus Media, removing iron, manganese and sediment., Filtered water flows down to the distributor screen, up the distributor tube, and out to the household piping. Once or twice a week, the Fleck 7000 control valve timer starts a backwash and rinse, called a 'regeneration' cycle. This typically occurs automatically in the middle of the night.

During regeneration, the MangOX Plus media is first backwashed thoroughly. During the backwash, water flows down the distributor tube and up through the MangOX media and out to drain, flushing out the accumulated iron and manganese and sediment.

After the backwash, the chlorine or hydrogen peroxide solution is sucked out of the solution tank, and the MangOX is rinsed and regenerated restoring the exhausted media to a fresh state where it can continue to remove iron and manganese. Any residual chlorine or peroxide is rinsed out to drain.

Maintenance consists of adding 1 cup of household bleach or hydrogen peroxide to solution tank once every 1—2 weeks.

Manganese Dioxide Filters (MangOX©, Filox©, Pyrolox©) Continuous Regeneration: Chlorine or Hydrogen Peroxide Feed

This method is called "Continuous Regeneration". Unlike standalone greensand or MangOX filters which use permanganate, chlorine or peroxide to regenerate the media intermitiently with each backwash, the MangOX media is "continually" regenerated.

The chlorine feed ahead of the iron filter super-charges the media and allows it to remove high levels of iron, manganese and hydrogen sulfide. Coliform and iron bacteria are killed, and tannins are oxidized. This type of iron filter system handles the worst type of water reliably and effectively.

How it Works: A small chlorinator pump automatically injects a small amount of chlorine or peroxide ahead of the iron filter. The system can use either chlorine or hydrogen peroxide. The chlorine pump is installed so that when your well pump turns on, the chlorine pump turns on, and injects a small amount of chlorine bleach or hydrogen peroxide.

The chlorine (or peroxide, or ozone) allows the MangOX-Plus filter media to remove high levels of iron, manganese & hydrogen sulfide. Iron bacteria are killed and the life of the MangOX media is extended up to 10 years. For most applications, no contact tank is needed, and the chlorine taste and odor is removed by the MangOX media.

For water very high in iron, hydrogen sulfide gas, or coliform bacteria, the optional contact tank is recommended.

• Removes Ferrous & Ferric Iron
• Removes manganese
• Removes low levels of hydrogen sulfide "rotten-egg" odor
• Kills bacteria & disinfects water
• Oxidizes tannins
• No need to use potassium permanganate.
• Works great with chlorine, peroxide or ozone gas

Chlorination controlled by existing well pressure switch. Most common method used. Lowest cost.

Chlorination controlled by Flow Meter "Proportional Feed". Allows chlorine injection point to be after pressure tank, or at point of use or entry to home.



Iron, Manganese & Odors Well Water Treatment CHEAT SHEET