Should I Install Whole House Water Filter Before Or After Water Softener?
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Wondering if you should install a whole house water filter before or after water softener?
Most of us in the developed nations are fortunate enough to have easy access to drinking water.
But not all the water that comes from our taps is equal.
This is why many people turn to water filter and softening systems to improve their household’s water.
Water filtration and softening are two different devices with two different jobs.
This then begs the question: What comes first, should you install a whole house water filter before or after water softener?
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Last update on 2025-03-20 / Affiliate links / Images from Amazon Product Advertising API
Should Water Filter Be Installed Before or After Water Softener?
Water Filtration vs Softening
Let’s start by having a look at exactly what water filtration and softening is.
Water Filtration
Clean water filtration is a process that reduces or removes contaminants or impurities from the water supply.
These includes particles such as iron, salt and more.
This is usually for drinking water.
These impurities include parasites, bacteria, fungi, viruses, as well as chemical or biological objects such as pesticides, iron, sulfur, fluoride, etc.
There’s more than one method of filtering when it comes to liquid:
- Physical barrier
- Biological process
- Chemical process
Many filtering systems use a combination of these methods in their various filtration stages.
The end product after filtration will have unequal levels of purity depending on the quality.
Please note that no clean water filtration structure can remove 100% of contaminants.
Water Softening
Softening is the process of removing calcium and magnesium that’s found in ‘hard water’.
Water softening does not reduce any contaminants such as iron.
Instead, it only deals with hard water.
The problem with hard water is that it causes scale build-up in appliances and plumbing, shortening their life-span.
You’ve probably seen scale build-up in your or coffee maker.
The scale (or limescale) is the result of the hardness of calcium and mineral deposits.
They have dried up and stuck to fixtures, appliances, or your water line.
Although a water cooker is easy enough to descale, it’s a lot harder when we’re talking about washing machines, dishwashers, and plumbing pipes.
By preventing hard water from entering your appliances in the first place, you can prevent this scale build-up ensuring your appliances can be used for a longer period.
Soft water also allows you to use less soap to clean and your clothes may wear out less quickly with repeated washes.
Hard water is not a health issue, but it is a nuisance for many households.
Do You Need A Water Softener If You Have a Whole House Filter?
Whether you need both a water filter system and a water softener depends on the kind of water that comes into your home.
Generally, most of the USA has hard water.
However, you should be able to get a water report from your local water provider to find out more about the quality of your particular water supply.
If you use a private well or rainwater, you can get the water tested by a certified lab for hardness.
This can help you decide exactly what kind of filter to consider installing a whole house water filtration system.
Why Do I Need All The Water In My Home Softened?
Even if you have a whole house water filtration device installed you can still have hard water with all the problems this causes.
To change hard water into soft water, you need a softening system.
And there are several advantages when considering the installation a whole house softening system:
- Whites stay whiter without the gray caused by hard water
- Appliances may last longer as scale will not build-up
- You don’t need to remember to remove scale from your washing machine, dishwasher, and other appliances
- The pipes may last longer without scale buildup
- Reduced soap curd makes your job of cleaning easier and quicker
- You’ll use less soap and shampoo which saves you money
If you only clean and soften your kitchen tap with an under-sink device or use a countertop system, you’ll lose these whole home advantages.
This is why it’s much better to install a whole house water softening device if you live in a hard water area.
How Does a Water Softening System Work?
There are essentially two types of water softening systems: salt-based and salt-free.
A salt-free softener is usually called a water ‘conditioner’ as it doesn’t truly soften the water.
Salt-free devices are generally considered healthier as they do not add sodium to the water.
Some cities are even banning traditional salt-based systems for health and environmental reasons.
Although they are effective at preventing scale and even eliminating pre-existing scale build-up, they do not provide many of the benefits reaped by actual water softening.
Which system you choose depends on where you live, the hardness of your water supply, and your personal (health) goals.
Keep in mind that measuring water hardness can be important to your health.
What Types of Water Filtration Options Are There?
There is a range of options for filtering the water you use at home, here are a few examples:
- Portable water filters that you can use on the go
- Fridge water filters that connect to your refrigerator for cold filtered water
- Counter-top water filters that you refill from the tap
- Under-sink water filters that clean water for just that one tap
- Whole house water filters that clean all the water that is used throughout your home
All these filtering systems are available at different price points and quality levels.
What Is a Whole House Filter?
Installation for whole house waters filters should be at the Point of Entry (PoE), right after the water meter.
This means that all the water in your house is filtered including the water for your washing machine, toilets, dishwasher, all taps, your bath, and shower, etc.
By having all the water in the house filtered, you don’t have to remember to grab the ‘special’ water from the filter jug or to use the separate tap on the sink.
A whole house water filter also means your shower will filter water without vapors from standard treated municipal water supplies.
The convenience and health benefits of a whole house water filter have led to the increasing popularity of these systems.
As you can see, water softeners and water filters perform different jobs.
In a whole house device, the installation of both filtration equipment and water softeners needs to be as close as they can to the point of entrance.
The question of where in your whole house water filter to install the softener is rather more complex than you’d guess at first glance.
Let’s have a look at the different sources people get their water from as this will influence the installation location of water softeners in your water system.
Where Do You Get Your Water From?
Households get their water from different sources such as private wells, rainwater, and municipal water.
Well Water
Around 13 million people in the US get their water from a private well.
Wells are supplied by groundwater or aquifers.
Because well water comes from groundwater the quality can be affected by seepage from fertilizers, underground fuel tanks, failed septic tanks, landfills, and other runoff.
If you get your water from a well you want to test the well water regularly to make sure you don’t ingest heavy metals, harmful chemicals, or pathogens that can cause illnesses.
The Centers for Disease Control and Prevention recommends that you get your well tested every year.
Another consideration with well water is turbidity.
Turbidity is the measure of the clarity of a liquid.
Things that cause water to be turbid include clay, silt, as well as other inorganic and organic matter.
As you can see, it’s important that you know the well water quality before installing a water system.
A well water filter starts with a pump to pump the water to the surface and then a water pressure tank to provide water pressure.
You can install any filter or softener after the water pressure tank but before any taps to appliances or faucets.
Rainwater
Rainwater harvesting is becoming more popular, especially as droughts and depletion of groundwater aquifers are increasing.
A rainwater harvesting set-up is similar to a well water set-up.
You’d harvest the rainwater in tanks, taking care to keep foreign matter and debris out with screens.
Then it will go into a pressure tank followed by a filtration system.
Filtration systems for rainwater usually contain a UV stage at the end or a chlorine injection stage to disinfect the water and ensure it’s free of pathogens.
Rainwater is an original soft water source as it doesn’t contain the dissolved minerals found in streams, groundwater, and municipal water.
Although rainwater will need one of the best filtration devices as it’s vulnerable to pollution from the environment, you won’t need a water softener.
So for this article, we’ll leave that one out of our considerations.
Municipal Water
If you have municipal water (sometimes called town water or city water) it is most likely treated with chlorine compounds.
Many people don’t like the taste and find the vapors when showering bothersome.
When installing a water filter you will want to choose one that specifically targets chlorine, such as a carbon filter.
After all, getting rid of the chlorine taste of water is one of the overriding reasons people cite for choosing a filtration system.
Municipal water enters the home usually at ground level or below and you install any systems as close to the point of entry to your home as you can.
Filtration Stages
To make it easier to decide if your water filter should come before or after your softener, you first need to understand that the filter device has different stages.
Generally, a filter starts by trapping the largest particulates in your water supply.
From there it works its way up to the finer particles such as iron.
Each filtration stage has a well-defined purpose in the process of targeting specific contaminants such as iron, pesticides and more.
A common three-stage filtration device starts by filtering out the larger particles through a filter often with 5-micron pore size.
That filter blocks every particle that’s larger than 5 microns but the smaller particles will still go through.
Those smaller particles will be filtered out at later stages.
Even though the pre filter that cleans through sediment only filters out the largest particles, it plays a key role in keeping the next stage filters as well as your water softener functional for a longer period.
Without this pre-filter, the other stages would need more frequent filter media changes.
This is because they would get blocked more quickly with the larger particles.
The next two stages are often from a carbon filter.
This includes a Granular Activated Carbon (GAC) filter to take out some of the chlorine taste and odor, and other contaminants.
An Activated Carbon Block (ACB) stage uses fine powder to filter out even more of the chlorine in treated municipal water, chemicals, contaminants such as lead, and volatile organic compounds (VOCs).
The downside of the activated filter is that it can reduce the flow-rate of the water resulting from it, which is a consideration when combining it with a salt-based water softener.
Additional post-filter stages can be added to a filtration device including a reverse osmosis process, ion exchange, ultraviolet disinfection, and ionization.
Your personal health goals, the particular contaminants in your local water supply, and your budget will influence what kind of water treatments you’ll want to install in your home.
Where Should a Whole House Water Filter Be Installed?
You understand now that the source of your water influences how you set-up your filtration system.
And you also understand that water filtering systems have different stages in the process each with their purpose.
You’ll by now also understand that where you install your filter and your softener in a whole house system depends on your specific situation.
Here are some general guidelines.
Where To Install The Softener In Well Water System
In a well water system, it is recommended to install a pre-filtering stage after the pressure tank to remove the larger particulates.
Especially if the turbidity of your well water is high you will want to use a sediment filter.
Using Sediment Filters
These types of filters are relatively cheap to replace and by installing them at the start of your set-up you protect all your other filtering and softening equipment.
If you use a water conditioner, a salt-free water softening system, you now run the water through the filtering stages as well as other filtering stages that you might choose to install.
After that, you install your water conditioner followed by any post-filtering stages such as UV disinfection or ionization.
However, if you use a salt-based water softener, as opposed to a water conditioner, it needs more water flow for proper backwash.
The backwashing cycle of a water softener is when water runs through the resin tank ‘backward’ at a fast speed.
This flushes iron minerals from the resin bed and out to the drain.
The filtering stages can reduce the flow of the water.
If that is the case in your set-up you can install the water softener before the carbon stages, but after the sediment filter to protect your equipment.
Another option is to install a higher quality carbon filter that still offers a good flow rate for the water softener.
Since there is no chlorine in well water, you don’t need to filter your water before the water softening system to protect the equipment.
Where To Install The Water Softener In a Municipal Water System
Most municipal water is treated with chlorine compounds.
Chlorine is a highly efficient disinfectant and is therefore added to public water supplies in many countries to kill disease-causing pathogens, such as bacteria, viruses, and protozoans, that commonly grow in water supply reservoirs and storage tanks.
As good as chlorine is at disinfecting water, it, unfortunately, deteriorates the resin in water softening systems.
This is the reason you would install your water filtering system before the water softener.
However, some people argue they would rather ‘sacrifice’ the resin bed in the water softener and replace it more often than having bacteria or microorganisms sitting in the resin tank or floating around in the system.
Allowing chlorinated water to enter the water softener would prevent any pathogens from taking hold there.
Another consideration is the flow needed for the backwash of the salt-based water softener.
This concern can be ameliorated by choosing a carbon filter with a good flow rate that’s still sufficient for the water softener.
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I’m Selling My House, Do I Take My Filtration And Softener Or Leave It?
The purchase of water treatment equipment is an investment in your home.
You could, therefore, consider a properly working water treatment system a selling point.
In that case, you will want to leave it when you move.
Another point in favor of leaving the treatment system in place is that it is specific for that water supply.
A water treatment system is not the same as a refrigerator or microwave, it not only meets your standards it’s also designed with your specific water supply in mind.
Before you decide whether to take the system with you or leave it at the house you will need to investigate the water supply at your new house.
Many homeowners don’t realize that your water can be completely different from the water at your neighbor’s house.
Variations in water sources can make all the difference in what’s in the water in your current home and what could be waiting for you in your new home.
The filtration system you’ve installed at your current home may be completely unsuitable for the new house.
It’s also possible that the water supply at your new house is not hard water at all and that you don’t even need a water softener.
If you do decide to take the water treatment systems with you, remember to make sure that you leave all the plumbing in good order for the new owners after you’ve taken all your equipment out.
Final Thoughts
I hope we’ve managed to clear your dilemma if you should install whole house water filter before or after water softener.
Placing any carbon filtration stages before the softener will take the chlorine out and protect the water softener.
Commonly, the filters are cheaper to replace than the resin bed in the softener tank.
On the other hand, some people worry about the risk of bacteria growing in the softener as the water going into the softener is no longer chlorinated.
A similar worry can be applied to well water, which is why some well water owners inject chlorine into their water tanks.
That said, most people opt to install their water softener after their water filtering systems.
And that choice depends on your specific water source and what you aim to achieve with your filtration system.
For any issues or if you have a clog, be sure to contact a plumber or professional.
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