Last Updated on December 29, 2023 by Richard
Got orange-red stains in your sink, dish washer, tub, clothes washer, and toilet? Or maybe those stains are gray or even black? Well, you desperately need an iron water filter.
But what kind of iron water filter is best for your home, RV or garden hose?
Well, I’ll show you how to filter through all of the many choices to get the best iron water filter for your needs.
Common Problems An Iron Water Filter Can Fix
Red iron water commonly also has poisonous arsenic, (smelly sulfur) hydrogen sulfide, and gray or black stains caused by manganese (metal).
Manganese is commonly bound to iron, and it’s responsible for the black or brown stains on your washed clothes, sinks, showers. 
Safe levels of manganese in your drinking water supply for anyone over one years old is 300 µg/L or less. Under one year of age the limit is 100 µg/L. However, taking a bath or shower with manganese water is not hazardous to your health. 
Ferrous Iron vs. Ferric Iron Water Filter Problems
The term “clear water iron” means the iron is dissolved in the water and can’t be seen, but it stains everything in the house. That’s ferrous iron.
The stains appear when the dissolved iron reacts with oxygen in the air. Which is now called ferric iron (rust).
There are expensive air injector water filter systems that turn clear iron water into solid rust so that it can be easily filtered out of the water. However, these systems fail after a few months, even though they are supposed to last for many years.
The problem is that the “educator/ injector” air injection valve gets covered with slimy partially oxidized iron particles and gets plugged up. Unfortunately, there is no easy way to clean the educator. But that’s not the worst of it.
The filter media in the tank that is used to trap the fully oxidized iron rust particles gets clogged up with the partially oxidized iron particles and stops working. Which means replacing that expensive filter media too.
Trust me on this, you don’t need the expense and headaches these iron eater air injection systems cause.
Doesn’t A Water Softener Remove Iron and Manganese?
Somewhat, but the amount it can remove is limited. Also, if you have too much iron in the water, the water softener resin will get clogged up with the iron that isn’t removed. Which is a problem you don’t want. More about that later.
Polyphosphate Water Conditioner To The Rescue?
Polyphosphate binds (sequestering) with the calcium and prevents it from binding with other calcium particles.
The end result is less scale build-up on your dishes, shower walls, inside your water heater, and inside your water pipes.
Also, polyphosphate binds with the soluble iron and manganese and prevents it from causing stains. Unless the water is boiled. In which case, boiling breaks the bonds between the polyphosphate and iron, resulting in iron stains.
Additionally, polyphosphate doesn’t actually remove dissolved iron, manganese or calcium from the water. So, they will still show up as turbidity when using a turbidity meter.
Polyphosphate won’t remove any iron metal tastes from the water, because the iron is still in the water.
Finally, polyphosphate is not an effective method when dissolved (ferrous) iron levels are greater than 2 mg/l. Nor when the combined ferrous iron and manganese is greater than 3 mg/l. 
- Protect Your Home From Scale – Protect the entire house from scale and filter algae, silt, sand, sediment, sand, and rust
- Water When You Need It – Large easy flow filters and high flow connections keep your water pressure high
- Don’t Waste Time on Maintenance – Our quick and easy to understand design means you can swap out filters quick and easy
- The Best Filtration – Made with food-grade slow dissolve sodium polyphosphate crystal beads giving you maximum chemical absorption
- Scale inhibitor combats hard water and cloudy build-up on glassware
- Convenient package including all necessary installation components
- Ideal for commercial / residential dish washer systems
- Includes housing, bracket, wrench, connections and three cartridges
- Dimensions are 6″ width x by 12″ length
Stinky Iron Eating Bacteria Can Ruin Your House
Iron bacteria eat dissolved iron and manganese, which creates a brown or blackish-brown slime. The slime will build up in your water pipes, well water pressure tanks, hot water heaters, toilet tanks, etc.
As the slime increases, it cuts of water flow and decreases water pressure. Where I live in Minnesota, the drain tile placed around the foundations of houses are often times plugged up with iron bacteria slime.
Iron bacteria is harmless to humans – except for the smell. To get rid of the smell and prevent the slime, use shock chlorination in your well and the pipes in your house. 
Removing Iron by Ion Exchange
That is what a water conditioner does. It exchanges calcium and magnesium ions for sodium ions.
Moderate amounts of dissolved ferrous iron can be removed by water softeners using various kinds of exchange resin filter media.
Therefore, not all water softeners are created equally. You need to check the specifications for any water softener you buy. Make sure that it can remove the amount of iron and manganese that is in your water.
Also, check to see how many gallons of water are used per minute to backflush the system. If your well can’t provide that amount of water, the softener will not be able to work properly.
If your water has higher dissolved iron content than the softener is rated for, you must first use an iron water prefilter.
Such as the APEC Water Systems Iron and Hydrogen Sulfide Reduction Replacement Water Filter, 4.5″x10″ (FI-KDF85-10BB) and 4.5″x20″ FI-KDF85-20BB shown below.
- Specializes in the removal of iron and hydrogen sulfide
- Superior taste and odor removal capabilities
- 10 inch filter treats up to 20,000 gallons
- Fits in all standard 10 inch whole house filter housings
- 10 micron nominal rating
- Specializes in the removal of iron and hydrogen sulfide
- Superior taste and odor removal capabilities
- 20 inch filter treats up to 40,000 gallons
- Fits in all standard 20 inch whole house filter housings
- 10 micron nominal rating
However, if your water also has higher levels of undissolved visible iron or manganese particles, you need a sediment prefilter. Which is placed after your well water pressure tank and before anything else.
Actually, this should be a standard practice for all whole house water filter systems.
The easiest to install and maintain sediment prefilter is the iSpring Reusable Spin Down Sediment Water Filter (WSP50GR) shown below:
- Press Gauge design. The whole house spin down sediment water filter has high impact stainless steel mesh filter screen rated at 50 Micron. Double threads on both ends: 1 inch MNPT and 3/4 inch FNPT, 1/4″ flush out fitting included
- Flushable and reusable. Take considerable workload off finer filters that follow behind it; helps create a multi-layer gradient filtration system for better filtration results and longer filter life. WSP series can be used for waste water treatment by spin down the sediment.
- Easy Installation. System can be installed in any direction thanks to the 360° rotatable head connection
- Long-lasting materials. The steel mesh filter cartridge and housing can be easily cleaned by rotating the scraper, saving time and effort on routine maintenance
- Excellent customer service. iSpring provides you lifetime support with high quailty of customer service
In my opinion, every house in America should have one of these, and one of the APEC Water Systems Iron and Hydrogen Sulfide Reduction Replacement Water Filters just mentioned above.
Then if you need a water softener and/or some additional filter system, you will save money, time and a lot of hassle maintaining the additional filters.
Greensand Iron Water Filter Systems Remove Higher Levels Of Iron
Actually, green sand isn’t sand at all, but balls of a glauconite clay mineral combined with other materials, which can exchange ions.
So, the green sand acts as the filter media in the water softener, and has to be regenerated now and then with a solution of potassium permanganate.
That is in addition to the periodic backflushing of the media to remove the ferric iron rust particles.
Greensand filters have been replaced by the newer ion exchange systems. Some of them use a granular “sand” that has a manganese dioxide coating, which replaces the original greensand product.
Greensand iron water filter systems have been replaced by newer ion exchange systems. Particularly the KDF 85 type systems I’ll talk about shortly.
Oxidation Of Ferrous Iron With Chlorine, Hydrogen Peroxide, and Ozone
When your iron and manganese levels are 10 mg/l or more you can use chlorine to change the ferrous iron into solid ferric iron, which is then filter out of the water.
However, the chlorine will cause the creation of trihalomethanes (THM) which must be filtered out. Usually with an activated charcoal filter.
A chlorine purification system should be designed and installed by a professional. Also, maintaining such a system can be dangerous. That’s due to the health hazards of chlorine liquids and gases. I can’t recommend a chlorine system for home use.
Hydrogen peroxide is commonly pumped into the water pipe with a chemical feed pump at the optimum rate needed for your particular water situation.
I used chemical feed pumps at the sewage plant to treat sewage with a flocculant. It’s very easy to do, but you need to have the space for a barrel of hydrogen peroxide and the small pump. Also, this is something you should have a professional install.
Also, you will have to test just how much hydrogen peroxide is needed. So, this will take some advanced planning to set up.
Ozone is another great oxidizer, but isn’t commonly used for whole house treatment (that I know of), because of the cost.
It does really well for purifying washing machine water. However, if you have high amounts of iron it will make the dissolved iron drop out as iron rust.
Which will show up on your white clothes. This can be cured by using O3 PURE Eco Laundry Washer System.
Or use the iron and hydrogen filter already mentioned, before the ozone treatment.
Ozone is often used to remove smells in the air. Also, ozone water will disinfect and clean vegetables, fruits, and just about anything you can think of.
Hunters use it to make their hunting clothes scent free.
Does your car stink? Ozone will kill the stink.
What Is KDF 55 and KDF 85 Filter Media and Which One Should You Buy?
KDF ® is a registered trademark of KDF Fluid Treatment, Inc.
They make two products KDF 55 and KDF 85, both of which are water filter media. The main ingredients are a combination of very pure copper and zinc in a granular form.
The copper and zinc granules create an oxidation/reduction (redox) reaction which reacts with the water contaminants to enable removal of them.
Actual removal is by filtration and/or backflushing of the filtering medium.
KDF-85 Whole House Complete Water Filter System with Sediment and GAC/KDF 85 Filters. Check it Out - Click Here
Also, various water filter products may combine the use of both KDF55 and KDF 85 in different ways to produce specific results. Both KDF medias are available in coarse, medium, and fine granule sizes.
Also, both products are quite similar, but only the KDF 85 filter media removes dissolved (ferrous) iron and hydrogen sulfide (rotten egg smell).
Both KDF 55 and KDF 85 remove:
- Hard water that creates “scale”
- Dissolved metals including: lead, chromium, mercury, nickel
- Fungus, various kinds of bacteria and algae
Some of the best iron water filter systems use the KDF85 filter media. However, if you have manganese in your water, you will probably need an additional filter. That is, unless the filter you buy is designed to also remove the manganese.
Big Blue Sediment, Carbon, and Iron & Manganese Reducing Filters. iSpring WGB32BM 3-Stage Whole House Water Filtration System w/ 20” x 4.5” filters. Remove Manganese and Iron – See it at Amazon
Well Water Softener & KDF 85 Iron Water Filter System
KDF 85 is made of 85 percent copper and 15 percent zinc which creates a minute electrical-chemical condition that stops bacteria from growing within the filter.
Also, a KDF 85 iron water filter removes any hydrogen sulfide smells from the water. That’s in addition to removing chlorine, iron, mercury, lead, and some manganese, along with other contaminants.
Premier Well Water Softener & Iron Reducing Water System uses KDF 85. Check it out – See it at Amazon
RV, Marine and Garden Hose Iron Water Filter
Camco’s EVO Premium RV/Marine Water Filter and the Camco 40043 TastePure RV/Marine Water Filter contains KDF 85 filtering media to remove iron and prevent bacteria growth in the carbon filter.
Both filters are designed to last for one camping season. The Camco EVO filter will provide greater water flow and water pressure than the Camco 40043 TastePure.
Washing Machine and Garden Hose Iron Water Filters
Here again, both of the Camco iron water filters could be used. Although, the bigger Camco EVO Premium RV filter would be the better choice.
Keep in mind that these are not designed for use with HOT water. The plastic will expand and contract with heat and will cause water leaks.
Also, the Camco TastPure is a 20 micron filter. Whereas the Camco EVO is a 5 micron filter. So, what I suggest, is to use both of them to get the best water quality.
First, the water should go through the 20 micron filter and then through the 5 micron filter.
Camco EVO Premium RV & Marine Water Filter, Greatly Reduces Bad Taste, Odor, Sediment, Bacteria, Chlorine and Much More (40631) Check the price at Amazon.
Camco 40043 TastePure RV/Marine Water Filter with Flexible Hose Protector Protects Against Bacteria, Reduces Bad Taste, Odors, Chlorine and Sediment in Drinking Water
The wider body Camco 40019 filter is a little more expensive, but provides a better flow rate and will last longer. See it at Amazon
The Best Whole House Iron Water Filter System?
The BEST system is a moving target, because everyone’s situation is unique. However, here is a proven system that will work for many people.
First, whether you have city water or well water, you need a spin down sediment prefilter . This prevents the other filters from having to be replaced so often. Which will save you money and time.
Also, many people buy water filter systems and then complain that the system didn’t work. The real problem was that they expected a 5 micron filter to filter out the larger sediment and sand too. However, the 5 micron filter will be plugged up pretty fast with the larger sediment particles. So, save your money and get the spin down prefilter.
Second, a water softener if you have hard water. The harder your water is, the more important it is to have a water softener to protect the other filters and your household appliances. If you don’t have hard water go to the “Third” item (next).
Let me say that some customers with well water did not need a water softener when using the “Third” item (next).
Third, this whole house 3 stage “Big Blue” manganese and iron water filter system . It also removes additional sediments, chlorine, VOCs, rust, industrial solvents, pesticides, herbicides, and more.
Fourth, an Ultraviolet Water Sterilizer to kill bacteria, parasites, and other microbes. Bacteria will multiply in any carbon filter that is not designed to kill bacteria. Often times even those anti-bacterial filters have a limited effect. So, be safe and get a UV filter.
Fifth, an optional iron water filter placed after the spin down sediment filter. This will take care of any residual rotting egg sulfur smells and reduce the iron content to a level that the water softener can handle.
Iron Water Filter Conclusions
From my reading numerous customer comments about the various iron water filter systems they have bought, this article will have saved you weeks or months of research.
There is no one perfect iron water filter system, but now you can judge for yourself what the best iron water filter solution is for you.
Many people skimp on how much they are willing to spend, because they think they don’t need everything I have suggested. However, the four or five items I have listed is an excellent system, and can be done at a reasonable price.
Do you have an iron water filter system that works? Leave a comment and let us know. Everyone will appreciate hearing about your success.