Iron and manganese are common contaminants in well water and groundwater. These naturally occurring metals can cause orange-brown stains on fixtures, laundry, and toilet tanks. They also create unpleasant tastes and odors in drinking water. High levels can clog pipes and reduce water pressure. Removing iron and manganese helps maintain clean water and protects your plumbing and appliances. Treatment options vary depending on the type and amount of these contaminants.
Sources of Contamination
Iron and manganese often enter water from natural sources like rocks and soil. Over time, these metals dissolve into groundwater. Rusty pipes, aging fixtures, and old water heaters can also release iron and manganese into your water. Human activities such as mining or poor wastewater disposal may increase contamination. Identifying the source is the first step. If corroded pipes are the cause, replacing them may fix the issue. A water softener or iron filter is usually needed if the metals occur naturally.
Types of Iron
- Iron appears in different forms in water, each needing a specific treatment.
- Ferrous iron (soluble) is dissolved and clear until it oxidizes.
- Ferric iron (insoluble) shows up as rust-colored flakes that can be filtered out.
- Bacterial iron forms when iron combines with bacteria, creating slimy, red-brown deposits.
Knowing the type of iron helps you choose the right solution—water softeners for ferrous iron, iron filters for ferric or bacterial iron.
Health Risks
Low levels of iron and manganese aren’t usually harmful. But high levels can cause stomach cramps, diarrhea, and other digestive problems. They may also stain teeth, skin, and hair. Iron can encourage bacterial growth, which can lead to hydrogen sulfide, causing a “rotten egg” smell. Removing these metals helps protect your health and improves the quality of your water.
Treatment Methods
Several methods effectively remove iron and manganese from water:
- Water softeners work well for low to moderate levels of dissolved iron and manganese.
- Iron filters remove solid iron particles and work best for higher concentrations.
- Oxidation systems use agents like chlorine or peroxide to convert dissolved metals into filterable forms.
Other options include catalytic carbon filters, soda ash injection, and retention tanks. The best system depends on your water’s test results. Regular maintenance ensures continued performance and protects your water from iron, manganese, and bacteria.
Frequently Asked Questions (FAQs)
1. How do iron filters work?
When water is underground in your well, it is usually clear in color, even though it may contain high levels of iron. This is known as ‘ferrous' or clear water iron.
Iron filters take this clear iron and transform it into rust or ferric iron in a process known as oxidation. These trapped particles are periodically and automatically backwashed out to drain, usually once or twice a week. Most iron filters remove clear water and ferric iron (rust).
The maximum level of iron recommended in water is 0.3 mg/L, which is the same as saying 0.3 Parts Per Million or PPM. When the iron level in water exceeds the 0.3 mg/L limit, the water may appear red, brown, or yellow 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 can become plugged with rust and sediment.
2. Which is the best iron filter for my application?
This depends on your well water chemistry. The first step is finding out if your cold water has a sulfur odor in it, or if it is just the hot water, and testing your water for iron, manganese, pH, hardness, and total dissolved solids.
Click here for low-cost, accurate water analysis.</p></p></p></p></p>
<p>For single-family homes, an iron filter that uses aeration combined with Pro-OX manganese dioxide filter media is recommended for most homeowners because it removes both types of iron, manganese, and sulfur odors. Other types available are Greensand Iron Filters (which use potassium permanganate powder) and Birm Iron Filters (which work for some applications but do not remove sulfur odors or manganese. In some cases, if the water has a very strong sulfur odor or has high levels of iron bacteria, hydrogen peroxide, or chlorine injection, a pump is recommended ahead of the Pro-OX iron filter.
3. What are oxidizing iron filters?
Iron filters oxidize the clear dissolved ferrous iron in water to an insoluble particle and trap the iron (rust) in the iron filter media. A periodic backwash cleans out the rust and flushes the filter media clean.
We recommend Pro-OX filter media as it is more powerful, removes higher levels of iron, and lasts the longest. Other types of iron filter media are available, including Birm, Greensand, MangOX™, Filox™, and Pyrolox™.
Oxidizing iron filters use either air, potassium permanganate, chlorine, or ozone to aid the filter media in oxidizing the iron. Pro-OX media is a solid manganese dioxide media, whereas most iron filter media use a thin coating of manganese dioxide over another media base.
Solid manganese dioxide is the gold standard for iron filtration media. It lasts for many years, often 15 to 20, and allows for faster filtration.
4. Do these systems come in different sizes?
Yes. The size of the system depends on the flow rate of your water in gallons per minute. The higher the flow, the larger the system required. It’s important to follow the recommended backwash flow rates.
5. Will there be a pressure drop through the system?
Properly sized, the system has a very low pressure drop at service flow rates, usually around 5 psi. Most people do not notice any change in household water pressure.
6. Can I route the backwash water to my septic tank?
Yes. In almost all cases, the backwash water can safely be routed to your septic tank.
7. Can’t I just use a water softener to remove iron?
Water softeners can remove dissolved clear water iron through ion exchange. However, iron, manganese, and hydrogen sulfide gas can eventually foul the resin.
If your water contains less than 2.0 ppm of iron and manganese combined and no sulfur odor, you may be able to use a good-quality water softener with a resin cleaner in the brine tank.
The resin cleaner helps remove buildup during salt regeneration. Still, we recommend using an iron filter before the softener for the best results.
8. What are “greensand” iron filters?
These filters use a specially formulated filter media made from glauconite greensand. The media has a coating of manganese oxide, which oxidizes iron and manganese on contact.
Greensand filters require potassium permanganate (a purple powder) to regenerate and clean the media.
9. Can I get assistance in choosing an iron filter system for my application?
Yes. Start by having your water tested, then contact our technical staff for help selecting the best iron filter system.
