Iron and Manganese
The first step to learn how to remove iron, manganese, and odor from well water is to understand a little about where iron comes from and the types of iron found in 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 you find iron in a dissolved state so water may appear clear when first drawn from the tap.
The maximum level of iron recommended in water is 0.3 mg/L. This is the 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.
Manganese is another metal that leaves stains. Instead of rust stains like iron, it leaves a brown or tea color stain on fixtures, dishes, and laundry. It also has a bitter taste which some describe as an asphalt or petroleum taste.
Odor and Taste
The water may also have a metallic taste and an offensive odor. Water system piping and fixtures can become restricted or clogged. Appliances such as water heaters, dishwashers and washing machines, can be plugged with rust and sediment.
Iron and manganese also give well 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.
Questions to Ask When Choosing an Iron Filter:
2. What is my well water chemistry? Do I have manganese, hydrogen sulfide odor, iron bacteria, or tannin in my water..or just iron? What is the pH (acid or alkaline)?
3. What is the source of the iron and/or odor? Is it only from the well water or is it also from corroding iron pipes or water heater?
4. What is the flow rate I have available in gallons per minute from my well pump or booster pump, to adequately backwash the iron filter I choose?
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
Clear Water Iron
Water may be clear when first drawn from a hose bib or faucet, but then turn rusty later. This is iron that is dissolved in the water but later will turn to rust once it is exposed to air.
Exposure to air can happen anywhere or anytime, such as in the toilet, washing machine, or bath. To determine the type of iron, fill a clean white 5-gallon bucket with water. If the water is clear without a tint or color, you have primarily ferrous iron.
Use an oxidizing iron filter such as Pro-OX or other manganese dioxide iron filters to turn the dissolved iron to rust form, where it is then filtered out by the iron filter. Periodic backwash keeps the Pro-OX filter media clean. Often these iron filters use aeration to enhance the oxidizing ability of the filter media.
Red Water Iron
Also known as ferric iron (rust) this is iron that has already been exposed to some oxidation and is no longer dissolved in the water. Rarely does water contain only ferric iron. Often part or some of the water is oxidized and the rest of the water has clear water iron.
As above, also use an oxidizing iron filter which removes both clear water iron and red water iron. If the water was from a storage tank or lake where 100% of the iron was ferric iron (rust) then a sand filter or filter cartridge would remove it.
Some waters contain high levels of tannins which can enter the well water from the surface. Materials such as organic leaves, grasses, and other plant materials cause Tannins. These organic compounds can bind with iron.
Use chlorine bleach, hydrogen peroxide, or ozone gas feed ahead of the iron filter with sufficient contact time by using a retention tank. After filtering with manganese dioxide iron filter, follow with an activated carbon filter. In some cases, if the iron is colloidal (microscopic particles that cannot be easily settled out or filtered) then alum or polymer coagulant feed may be needed to clump the particles into larger particles that can be filtered.
Iron bacteria is a general term used to describe various species of bacteria that use iron to live and grow. Iron becomes part of their cell walls and the end result is a slimy stringy growth that can be seen in toilet flush tanks. The stringy growths can also line pipes and build up in water tanks, fixtures, and appliances.
Use chlorine bleach feed to disinfect the water and kill the iron bacteria, followed by a Pro-OX iron filter. A carbon filter can be used after the iron filter to remove any residual chlorine. Chlorine bleach is much more effective at eliminating iron bacteria than hydrogen peroxide however, ozone is another option that is effective as well.
Use Home Tests to Find Out What’s In Your Water
The best way to find out is to do a water test of the water right from the well before it enters the house. If this is not possible, then run the water for 5 to 10 minutes so you know the water is coming right from the well.
A water test is important to know which type of iron filter to use and if your water is acidic or not.
A water test will tell you how much iron you have. This knowledge helps you to choose the type of approach or system you should use to treat it.
Tests should include alkalinity, hardness, hydrogen sulfide, iron, manganese, pH, and total dissolved solids. If the water has a tea color to it or has a yellowish clear color to it, then a tannin test is recommended as well.
You should always include a pH test, which indicates if the water is acidic or alkaline. The ideal pH for iron filters to work properly is between 7.0 and 8.0, which is considered neutral and not acidic.
For health-related concerns include a test for total coliform, e-coli (fecal coliform), lead, and nitrate. Complete mineral, metals, and bacteriological tests from a State certified laboratory are recommended; especially if infants and children will be drinking the water.
When the source of your water is a public water system and you experience iron-related problems, it is important to contact your water company to determine whether the red water is from the public system or from the home’s plumbing or piping.
Do a Quick Physical Inspection of Your Water and Pipes
If you are experiencing iron or rust staining, it is important to determine the source, whether from the well water or perhaps from corroding pipes or fixtures.
Usually, the source of the iron is from the well water itself, as iron naturally occurs in many groundwaters.
In some cases, the staining may be caused by old galvanized iron piping or fixtures which have been corroded, making the water rusty.
Run a hose bib or tap as close to the well as possible and fill a white 5-gallon bucket or other container and check the color of the water, noting if there is any sediment present.
Notice if there are odors. If you smell a “rotten egg” odor, this is hydrogen sulfide gas coming right from your well water.
Manganese can make your water smell like oil or asphalt. In case your water smells like cucumber or sewage, it is usually due to iron and/or sulfur bacteria.
Run the 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 could interact with the anode rod in water heaters. This interaction may result in hydrogen sulfide gas only in the hot water. To solve this, change the anode rod to an aluminum rod.
Even if there’s no odor in the cold water but the hot water smells like rotten eggs, then you can also add a pint of store-bought hydrogen peroxide to the water heater and let it sit for 4 – 6 hours. This will often kill the odor for weeks or months. There are special filter strainers that make it easy to add peroxide to the water without having to take apart the piping.
Check Your Well Pump Flow Rate
Flow rate is defined as simply how many gallons in one minute can be pumped from the well. This is determined generally by the size of your well pump. It is also affected by the capacity of your well.
For example, if your well pump can fill a 5-gallon bucket in 60 seconds direct from the well, you can consider you have 5 Gallons Per Minute, or 5 GPM.
Most homeowners have a standard single-speed submersible pump with a pressure tank on their private well. This test is for this standard type of pump and pressure tank. If you have a ‘constant pressure’ or variable-speed pump, this test as described below won’t work.
A good flow rate is required in order to be able to backwash the filter systems properly. An adequate flow rate is also required in order to provide good water pressure to the home.
Count the gallons “drawn down” from the pressure tank and the time between the cut-in and cut-off cycle of the well pump. This is known as pressure tank ‘draw down’.
Easy Steps To Take to Find Our Your Well Pump Flow Rate:
1. First, allow the well pump to build up to full pressure by running water in the home or from a hose bib or faucet until you hear the well pump kick in or pressure switch points click.
2. Close the faucet and make sure no water is being used in the home. Well pump will build up pressure for a few minutes and then pressure switch will shut off well pump.
3. Next, open a hose bib (also referred to as a ‘spigot’ or ‘faucet’) anywhere near or after the pressure tank.
4. Run the water into a 5-gallon bucket, noting how many gallons you collect. If bucket fills up, dump out water and keep measuring and filling.
5. Measure the number of gallons drawn down from the pressure tank until the well pump turns on.
6. When you hear the pump turn on, immediately close the hose bib.
7. Time the period in seconds it takes for the well pump to build back up to pressure that is, between the cut-in and cut-out of the pressure switch. The pressure switch turns on the pump at a lower pressure and turns off the pump when it reaches a higher pressure.
8. The formula for determining the flow rate is: gallons are drawn down (that were measured above), divided by the seconds required for recovery, then multiplied by 60:
(Gallons / Seconds) x 60 = Gallons per Minute (GPM) flow rate..
9. For example, if 20 gallons are drawn down and it takes 120 seconds to build pressure back up, then: 20 divided by 120 = .166. Then multiply .166 x 60 = 10 gallons per minute flow rate.
10. So you have 10 GPM flow rate.
11. The next 2 posts will explain the step-by-step procedure on how to remove iron, manganese, and odor from well water. You can read the next step after downloading your iron treatment guide.
Want more detailed info on iron removal now? Get the FREE The Complete Guide To Iron Treatment:
Do A Quick Inspection and Test Your Well Water
How to remove iron manganese and odor from well water? The first step is to determine the source and find out the basic water chemistry.
Usually, the source of the iron is from the well water itself, as iron naturally occurs in many groundwaters. In some cases, however, the staining may be caused by old iron plumbing which has been corroded, making the water rusty.
The best way to find out is to do a water test of the water right from the well before it enters the house. If this is not possible, then run the water for 5 to 10 minutes so you know the water is coming right from the well.
A water test is important to know which type of iron filter to use and if your water is acidic or not. A water test will tell you how much iron you have, which helps in choosing the type of approach or system you should use to treat it.
Tests should include alkalinity, hardness, hydrogen sulfide, iron, manganese, pH, total dissolved solids. If the water has a tea color to it or has a yellowish clear color to it, then a tannin test is recommended as well.
It should always include a pH test, which indicates if the water is acidic or alkaline. The ideal pH for iron filters to work properly is between 7.0 and 8.0, which is considered neutral and not acidic.
For health-related concerns include a test for total coliform, E-coli (fecal coliform), and nitrate. If infants and children will be drinking the water, a complete mineral, metals, and bacteriological test from a State-certified laboratory is recommended.
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 the water smells like oil or asphalt this can be from manganese. If the 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.
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.
Odor Identification and Solutions
- Does the cold well water have an odor right out of the well, from an outside hose bib?
- If there is an odor to the water, do all the taps in the home have the odor? Are some taps in the house (such as upstairs, or from a particular bathroom or fixture) have greater odor than others?
- Does the hot water have the odor only, with the cold water having no odor?
- The best way to test odor is to use a tall drinking water glass or wine glass and have at least two people perform the test by drawing the water and noting the odor.
- How would you characterize the odor?
|Asphalt or oily odor||Manganese||Iron filter that removes manganese ( Pro-OX, MangOX, Greensand, Pyrolox)|
|Oily odor||Petroleum||Oil removal media such OilSorb, followed by activated carbon filtration.|
|Cucumber odor||Iron or sulfate-reducing bacteria||Disinfection with chlorine or ozone or peroxide, followed by filtration|
|Earthy or grass odor||Geosmin||Produced by actinomycetes, blue-green algae, and green algae.|
|Garlic odor or taste||Methane gas||Off-gas into an open storage tank, ventilate well and use caution in treating this problem; methane is flammable|
|Metallic odor||Iron, manganese, or copper||Determine cause by testing water|
|Pond or Algae odors||Bacteria, organic matter||Disinfection with chlorine or ozone , followed by filtration|
|“Rotten egg” odor||Hydrogen sulfide gas||Chlorination, aeration, ozone injection, hydrogen peroxide, followed by filtration|
|Sulfur bacteria||Chlorination, aeration, ozone injection, hydrogen peroxide, followed by filtration|
|Sewage odor||Leaking septic tank||Repair or re-locate septic tank or well|
|Bacteria||Disinfection with chlorine or ozone or peroxide, followed by filtration; or repair or relocate septic tank or well|
Pressure Tank with Submersible Well Pump
How It Works:
The submersible pump in well (1) is controlled by the pressure switch (7). When pressure in pressure tank (4) drops below a preset level (typically 40 to 60 PSI) the pressure switch turns on well pump. The well pump continues to run until the pressure in the pressure tank builds up, and the pressure switch reaches the maximum pressure setting. The pressure tank contains a pre-charged airbag to moderate pressure in the piping system.
Check for Pipe Corrosion & Scale Build-up
Sulfur odors can cause sulfuric acid to build-up in water and corrode piping and fixtures. 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 rust-colored 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, say you decide you want to install an iron filter system for your house. They come in different pipe sizes, such as ¾” 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 an iron filter 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. The circumference is the distance it takes to go around the pipe once.
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.
Learning how to remove iron manganese and odor from well water is not difficult if you follow a few simple steps!
The 3rd and last part of this 3 – part series talks about what types of systems work best and more detail on how to remove iron manganese and odor from well water.
Now that you know your basic water chemistry and well flow rate, it’s time to choose the lowest cost and the best solution to treat your water.
Oxidizing Iron Filters
Iron filters oxidize the dissolved ferrous iron in water to an insoluble particle. Then the filter traps the iron (rust) in the iron filter media. A periodic backwash cleans out the rust & flushes the filter media clean. Various types of iron filter media are available including Birm, including Greensand, Pro-OX, Filox™, & Pyrolox™.
Oxidizing iron filters use either air, potassium permanganate, chlorine or ozone to aid the filter media in oxidizing the iron. Some brands are Filox™, Pro-OX™, and Pyrolox™. They are all solid manganese dioxide media. Most iron filter media uses a thin coating of manganese dioxide over some other type of filter media. Solid manganese dioxide media are the gold standard for iron filtration media. The media lasts for many years, often 15 to 20 years and these systems can filter the water at a faster rate.
The solid manganese dioxide types of filter media are the gold standard for iron filtration media. The media lasts for many years, often 15 to 20 years. These systems can filter the water at a faster rate.
Which Type Of Iron Filter is Best?
For best results, lowest maintenance, and longer life we recommend a high purity manganese dioxide filter media such as Pro-OX Iron Filters. Our company has customers with iron filters that have the same manganese dioxide media filters installed over 10 years ago. The filter media lasts many years longer than greensand, or other manufactured, coated filter media.
If sulfur odors or manganese are present, we recommend that you use a chlorinator or ozone injection system in front of the iron filter. The Air-Charger type (Pro-OX-AIR) systems work the best if you have iron and sulfur odor, but no manganese or iron bacteria,
Air Charging Iron Filters Remove Iron, Manganese and Sulfur Odor
The air charge iron filter, as a single tank system, is an efficient and cost-effective system for the removal of iron and sulfur.
When used with a solid manganese dioxide filter media such as Pro-OX, it can last for many years with little or no maintenance. No chemicals are required.
This type of iron filter maintains an “air pocket” in the top of the tank while the system is in service. As the water passes thru the air pocket, iron and sulfur are oxidized. Additionally, dissolved oxygen is added to the water. The iron filter media bed then removes the iron and sulfur from the water.
Air charger-type iron filters can generally remove up to 8 ppm hydrogen sulfide and up to 10 ppm Iron. The backwash removes accumulated iron and replenishes the filter media bed and adds a fresh air pocket to the system.
The unique 5900e control valve allows the air pocket to be replenished each night, without having the iron filter go through a complete backwash.
Other Air-Charger Iron Filters must go through a complete backwash each night, in order to replenish the air. This wastes thousands of gallons of water each year.
The 5900e-AIR saves water by being able to draw in air, independent of the backwash. The Pro-OX 5900 AIR is able to put the whole oxidation process inside one tank, keeping maintenance costs and downtime to a minimum.
This type of iron filter is one we recommend most often as it works best for most of our customers and is the easiest to maintain.
When Iron Bacteria or High Levels of Manganese or Sulfur Is Present Use Chlorine Injection OR Ozone Injection
If manganese is present over 0.2 PPM, we recommend a chlorine feed (the water be chlorinated) ahead of the iron filter. A small amount of chlorine is automatically injected by a chlorine pump prior to the existing well pressure tank. At these low levels of chlorine (under 10 ppm) the pressure tank is not affected by the chlorine.
The contact tank allows some time for the chlorine to work and dissipate. As the water flows into the Pro-OX filter all iron, manganese and hydrogen sulfide are filtered out. After the Pro-OX iron filter, a carbon filter removes all trace of chlorine.
Air Compressor Systems Aid in Removing Iron and Manganese
This type of iron filter uses a compressor to inject air into the water. This system uses a separate tank to inject and aerate the water and is highly effective at eliminating sulfur odors and oxidizing higher levels of iron. It will not remove iron bacteria, but it does offer a higher level of aeration than a standard Air-Charger type iron filter. The drawback is higher cost, and for most home well water applications, the Air-Charger is all that is needed.
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.
You can use air compressor systems with various iron filter media such as Birm, Greensand, and Pro-OX. We recommend Pro-OX manganese dioxide filter media as it lasts for many years. With Pro-OX (also Greensand) a chlorinator or ozone pre-treatment system could always be added later if iron bacteria were present.
The air compressor aeration tank is typically installed after the pressure tank and before the iron filter. The compressor can be wired so it turns on each time the well pump runs and re-charges the aeration tank with fresh air. It can also be set up on a timer so it refreshes the aeration tank one or more times a day automatically.