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Home » Water Softeners » Iron Filter vs Water Softener

Iron Filter vs Water Softener

By: Craig Smith
Last Updated:
iron filter vs water softener

When trying to resolve mineral-related issues with your home’s tap water, it can be confusing when it comes to determining whether to use a water softener or iron filter to clear up these problems.

Some people even assume the two perform very similar functions. It’s something that’s definitely not the case.

That’s why I want to take the time to discuss further with you what water softeners and iron filters are specifically designed to do, how they do it, and what are the advantages and disadvantages of using each of these proven water treatment methods.

The information in this article is based on both extensive research and what I know about treating iron and hard water-related problems from my extensive swimming pool maintenance background.

My goal is to explain everything in very understandable terms so you can make a sound choice as to whether a water softener or iron filter purchase is right for you.

What is an Iron Filter?


Although iron filters do their job very well, they are not as well-known or found in as many homes as water softeners. This is probably because more homeowners experience hardness issues with their tap water than they do iron-related problems.

Do not confuse that with meaning that the problems caused by having iron in your household water will not cause you some real headaches because they certainly can. That’s what makes removing iron from your tap water so important and there is no better way of doing that than by installing an iron filter on your incoming water line.

It’s also worth noting that you might hear iron filters sometimes being referred to as ‘oxidation filters’. They will do more than just remove iron from your tap water too. This includes filtering out magnesium and foul odor-causing sulfur particles.

Iron filters almost completely remove iron, sulfur, and magnesium from tap water through oxidation. The special media inside of them that filters iron out of tap water is placed in the bottom third of the system’s tank (see diagram below). At the inside top of an iron filter’s tank is the air that’s injected into the system and in the middle is water.

Elemental iron in water is generally found in one of two different forms. This includes unseen & tasteless ferrous iron in solution and rust particles called ferric oxide (there is also somewhat rare iron bacteria). Ferric oxide can be filtered out of tap water fairly easily but that’s not true of ferrous iron.

water softener diagram

It will pass right through a filter untouched and it’s the substance that’s most responsible for causing iron-related tap water issues. This is why you need a special piece of treatment equipment such as an iron filter to eliminate both ferrous iron and ferric oxide from tap water.

Untreated water will enter into the iron filter at the top where the air is injected into the system. When the ferrous iron is exposed to the air at the top of the tank, it will come out of solution in the form of ferric oxide. Now 99.9% of all of the iron in the tap water should be in ferric oxide form.

This ferric oxide travels through the water in the middle of the tank and then continues to the filter media where it becomes trapped as it comes into contact with it. A periodic backwash cycle will then rinse the trapped ferric oxide out of the media and out of the system.

If an iron filter does not resolve iron issues with your tap water, then your household water will need to be tested for the presence of iron bacteria.


They do a great job at removing iron, magnesium, and sulfur

It’s almost an understatement to say that a quality iron filter will do a great job of removing iron from your tap water. That’s what makes them the clear #1 water treatment method for dealing with moderate to severe iron issues in household water.

Setup is fairly simple

Iron filters do not take up much space or require anything too complicated to set them up. The control head at the top of the tank simply plugs into an electrical outlet and an incoming water line brings water into it and there is also an outgoing water line from it. A drain line will also need to be installed to handle the wastewater from backwashing.

Low maintenance

Although iron filters are not maintenance-free, once they are in place it takes very little effort to keep them running efficiently. The only real maintenance steps that are required for you to keep them operating is the periodic replacement of the filter media. Some have a sediment filter inside of them too that has to be cleaned once in a while.

Chemical & salt-free process

Unlike a water softener, no salt has to be added to these water treatment devices to enable them to do their job. No chemicals or other substances are needed during their filtration process either.


They can be costly

When you look at an iron filter it really may not seem to you there is much to them. But this can be very deceiving when it comes to purchasing one. A good oxidation-type iron filter will usually set you back around $600 or more.

Creates wastewater

To keep their filter media working more efficiently, iron filters go through what is known as a backwash cycle. This cleans out the filter media inside of them. A byproduct of this is a lot of wastewater is created during the backwashing process.

Not a good stand-alone water filtration option

These are not a good stand-alone filtration option at all unless the only concern you have with your tap water is filtering out iron, magnesium, and sulfur. That’s why iron filters are almost always found working in conjunction with other types of water filtration setups.

These completely remove healthy iron minerals

As was mentioned, iron filters will remove as much as 99.9% of the iron in the water that passes through them. That means you can no longer count on your drinking water to provide you with iron which in small doses is considered to be a healthy mineral.

What is a Water Softener?

A whopping 85% of the water supply in America has some level of hardness to it. That’s why water softeners, which were specifically made to tame hard water conditions in a home, are such popular items. There really is no better way to efficiently remove calcium, magnesium, and other hard water-causing particles from your household water supply.

How Do Water Softeners Work?

Water Softeners

There are other water purification devices that some refer to as water softeners but none of those uses salt in the hard water treatment process. These salt-free water treatment systems will only condition water, unlike traditional salt-based water softeners which almost completely remove all hard water-causing compounds.

Water softeners do this by using a process called ‘ion exchange’ and it works very well. These are systems that are composed of two tanks. One has special resin beads at the bottom of it and the other is the brine tank where the system’s salt solution is kept.

There will also be a control head on the resin tank.

The resin beads at the bottom of the resin tank are negatively charged. These beads sit in the brine solution that’s fed into the resin tank from the brine tank. The positively charged sodium ions in the brine solution coat and cling to the resin beads.

The tap water containing hardness-causing minerals then comes into the top of the resin tank and flows downward toward the resin beads that are coated with sodium.

Hard water causing minerals such as calcium and magnesium are more positively charged than the sodium ions clinging to the resin beads are. This causes the hard water minerals to displace the sodium ions and coat and cling to the resin beads.

The newly freed sodium ions and now softer water will then travel into your household water supply.

Just as with the iron filter, a backwashing process keeps the resin beads clean and washes the trapped calcium, magnesium, and other hard water causing compounds out of the system.

The ion exchange process that water softeners use will even remove small amounts of iron. But make no mistake about it, water softeners are a poor option if you are experiencing problems caused by having a moderate to high amount of iron in your tap water.


They offer a total hard water solution

Once water softeners have treated the tap water that passes through them, a significant amount of hard water-causing particles will have been removed from your household water supply.

Your tap water will have a ‘softer’ feel to it

Many people can feel the difference between hard and soft water. Most describe it as feeling softer and lighter on their skin.


They take some space to set up

Since a typical water softener setup consists of two tanks, ingoing & outgoing water lines, and an added drain line, it takes a good amount of free space to set them up in.

Possible poor water taste

One of the byproducts of traditional water softeners is that soluble sodium will travel into your home’s water supply along with the now soft water. You and your family may not like the taste the sodium adds to your water.

Removes healthy minerals from tap water

Calcium and magnesium are considered essential minerals. Tap water is one source where you will typically get them. That will no longer be the case if you have a water softener that almost totally eliminates these minerals.

Increased sodium intake in the diet

This is not the preferred type of hard water treatment equipment for those that are advised against having additional salt intake into their bodies.

Produces large quantities of wastewater

The backwashing cycle of the system that’s used to keep the resin beads functioning also creates much wastewater. This is probably not something that will go over well with you if you are an environmentally conscious individual.

Filtration vs Ion Exchange for Iron Removal

There is little debate when it comes to iron filters being the better of these two water purification devices when it comes to removing the nuisance-causing iron that’s found in your tap water. It’s not even close.

As was mentioned, if you have a small amount of iron in your tap water and a high level of hardness, then you might be able to get away with using just a water softener in this case. But for instances where your home water iron level is moderate or higher. A water softener definitely will not cut it.

So any time that you are trying to address having so much iron in your water it is causing you some problems, choose to go with an iron filter. You will be very satisfied with the results.

Do I Need an Iron Filter and Water Softener?

This is a fairly simple question to answer. Iron filters are specifically made to tackle iron problems in tap water and water softeners do a great job of eliminating hard water issues.

So combining a water softener and iron filter is never a bad idea if you have both high iron and hard water conditions present in your tap water. I do caution here that this still may not be enough to get your tap water to the level of purity that you desire.

That’s why even if you have a water softener and an iron filter, you would want to consider adding another water purification device such as a reverse osmosis filter. That would be a water purification setup that would significantly enhance your home’s water quality.

A Few Final Words on Iron Filters vs Water Softeners

Both hard water and iron in tap water bring along with them an abundance of nuisance-causing problems.

That includes time wasted trying to keep bathroom fixtures cleaned, clothes being stained, and appliances that use electric heaters needing repairs much more often than normal.

So if you have iron or a significant level of hardness in your home’s water supply, then an iron filter or a water softener are very worthwhile investments.

My advice is to strongly consider each of these effective water treatment options if you want to target the specific water impurities that each one removes.

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Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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