How Do Well Water Filtration Systems Work?

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You’ve probably heard that a well water filtration system is one of the best investments for most private well owners. But what are these systems, and how exactly do they work? What do they remove? How do you keep them working over the years?

In this guide, we’ve shared the answers to all these questions and more.

📌 Key Takeaways:

  • A well water filter system is a multi-stage filtration system that targets a range of common contaminants in well water.
  • Most whole house well water filtration systems have three stages: a pre-filter stage, a main filter stage, and a post-filter stage.
  • Well water filters work by trapping or pulling contaminants out of a water supply, preventing them from damaging your pipes and appliances.

🤔 What Is A Well Water Filtration System?

A well water filtration system is a kind of water filter system that removes common well water problem contaminants.

Most well water filter units are installed as point of entry (POE) whole house filters. That means they remove contaminants from your main water line at its point of entry into your home, protecting your entire plumbing system and appliances from impurities.

When you install a whole house water filter for your well, you can wash with, cook with, and drink water that’s clean and safe for use around your home.

Springwell WS well water filter system app and sediment filter

🚰 How Do Well Water Filtration Systems Work?

Well water filtration systems usually have three separate stages of water treatment: pre-filtration, a main water treatment stage, and post-filtration.

1) Pre-Filtration

The pre-filtration stage removes large particles of sediment, such as sand, soil, rust, and silt. Most pre-filters are sediment filters or multimedia filters.

Sediment filters are a key stage in most whole house water filter units. Not only do they protect your plumbing and appliances from contaminants that could clog and damage them; they also prevent the later filter stages from getting clogged with sediment, extending their lifespans.

2) Primary Water Treatment

The main water treatment stage tackles the key problem contaminants in well water.

There are different filters for different purposes.

Tank-based backwashing filters, like air injection/oxidation systems, are a popular choice for well water treatment because they remove high levels of iron, manganese, and sulfur.

In a cartridge-based water filtration system, iron, carbon, and KDF filters are often used. These filters treat contaminants including iron, pesticides, heavy metals, and other chemicals.

Springwell WSSS well water treatment system with UV

3) Post-Filtration

The treated water then flows through a final filter stage. This could be a polishing filter that removes lingering contaminants not targeted by an earlier filter stage, or a filter with a separate, dedicated contaminant removal focus.

UV purifiers are common post-filters in whole house water filter units for wells. These filters kill bacteria, viruses, and other microorganisms with ultraviolet light, making well water safe to drink.

🧫 What Do Well Water Filters Remove?

Well water filters can remove the following contaminants:

  • Iron
  • Sediment
  • Rust
  • Volatile organic compounds
  • Pesticides
  • Herbicides
  • Nitrates/ nitrites
  • Bacteria
  • Organic contaminants
  • Heavy metals

📌 Not all well water filters remove every single common drinking water contaminant, which is why it’s so important to test your water and work out which contaminants you think are the most important to remove.

We’ve shared more detail on which well water filters can remove which contaminants below.

📖 Types of Well Water Filters

The most common types of well filters, and the impurities they target, are listed here.

Sediment Filters

Sediment filters treat large particles of sand, silt, dirt, dust, rust, and other sediment in well water.

These filters may be used as standalone filters or installed as pre-filtration upstream of a multi-stage whole house water filter system to protect the later filter stages.

The average lifespan of a sediment filter is 3-12 months, depending on the filter’s micron rating and your water’s sediment level.

Sediment water filter

KDF Filters

KDF filters use oxidation-reduction to remove contaminants with water, and are often used in combination with other filter media in multi-stage whole house water filter units.

There are different types of KDF filters that remove different groups of contaminants, including lead, mercury, iron, hydrogen sulfide, chlorine, and bacteria.

Kdf media

Air Injection Filters

Air injection/oxidation filters are tank-based well water filter units that reduce iron, manganese, and sulfur in a well water supply.

These systems are known as backwashing filters, which means they send water back through the filter media to remove the accumulated contaminants.

Springwell WS1 Well Water Filtration System

Carbon Filter Cartridges

Carbon filters are more beneficial when used to treat chlorinated city water – but you can still find them in many well water filters.

A carbon filter can reduce chlorine (usually unnecessary for well water supplies), as well as some volatile organic compounds, pesticides, herbicides, and other chemicals affecting water’s taste and smell.

UV Purifiers

UV purifiers use a UV light to kill bacteria and other microorganisms in a water supply.

The UV process involves sending water through a UV chamber, where the water is treated with ultraviolet light. This damages the DNA of pathogens and makes them incapable of replicating.

UV purifiers are often used as a final stage after other filtration stages because they’re only effective on clear, non-turbid water.

Uv purification system

🔎 How to Know If You Need a Well Water Filtration System

Wondering whether a well water filtration system is right for you? Here’s what you should do.

Consider Your Water Quality

You’ve probably tasted both well water and municipal (city) water in your lifetime.

When you drink the water supply from your well, does it taste different from normal tap water? Is there a metallic or dirty taste? Does it smell like rotten eggs?

Also consider how your water looks. Can you see floating particles? Does your water have a brown or orange tinge?

Finally, consider the physical signs of drinking water contamination. For instance, iron-laced water may stain your fixtures orange, while manganese will leave black stains, and hard water minerals will leave chalky, white scale deposits.

Test Your Water

Not all well water contaminants are detectable by taste, smell, or sight. That’s why we strongly recommend testing your water for certain common well water contaminants, regardless of what your drinking water looks, tastes, or smells like.

📌 For the most accurate results, buy a test kit from a laboratory. Professional lab testing usually costs $150-$600, so it’s not cheap – but it’ll give you the most reliable insight into your water quality and parameters.

You can choose to test for individual contaminants or buy a tailored test package designed for regular well testing.

What should you test for? We recommend buying a test that detects the following:

  • pH levels
  • Iron
  • Hard minerals
  • Copper
  • Lead
  • Nitrates/nitrites
  • Coliform bacteria
  • E. Coli
  • Fecal coliform

You should also test for any other contaminants that you’re concerned about, or anything that you’ve been made aware of by your local authority.

How often should you test your well water? There are several occasions when you should conduct a water test:

  • Once a year – General testing to account for potential changes to your water quality, as recommended by the National Groundwater Association
  • More frequently – If and whenever you notice changes to your water quality, if your local region encounters known water problems, if a natural disaster occurs, if your water looks, tastes or smells different, after you repair or replace a well component, and if another source of contamination is present (such as leaking septic systems)
Taking water sample from faucet

📝 What To Consider When Choosing a Whole House Well Water Filter

There are tens of whole house water filtration systems available for well water today. Choosing the filter that’s best suited to your needs can be a bit of a chore.

To make your search as easy as possible, consider the following factors when browsing your options:

Your Budget

Before you start looking at whole house filtration systems, establish your budget.

You’ll need to set aside at least $600 for a quality multi-stage whole house water filter. Most systems cost in the range of $800-$2,600, depending on their design, size, and complexity.

Alongside the initial cost of a well water filter, you may also have to pay for a professional installation, which costs in the $150-$300 range.

Plus, there are long-term maintenance costs to consider. Whole home well filters cost $50-$250 per year on average to maintain, depending on the number of filters and types of filters that need replacing.

Your Water Quality

Your water quality is an equally important consideration to make.

Take a look at your drinking water test results. Which contaminants are the biggest problem in your water supply, and which do you want to remove the most?

Once you know these contaminants, you can choose a suitable whole house well water filter to remove them.

Tap Score untreated water test results

Your Water Usage/ Household Size

Your household size and your daily water usage both determine the size and capacity of the water filter system you need.

Most families of 2-4 will be fine with a system that has a flow rate of 8-12 GPM (gallons per minute). But if you have 3+ bathrooms or a large home, or you use more water than usual, you’ll need to upgrade to a larger system that won’t cause your water pressure to drop.

Installation & Maintenance Preferences

Also consider your installation and maintenance preferences.

Are you good at DIY? If so, you probably won’t mind the challenge of installing a whole house well water filter yourself. If DIY isn’t your strong point, you’ll need to pass the job on to a plumber. Most well filters are designed to be installed by the user, but there’s still an element of skill involved.

As for maintenance, decide whether you prefer a system that’s virtually maintenance-free, or whether you’re happy to replace several filters throughout the year.

If you want a system that’s as low-maintenance as possible, consider buying a tank-based whole house filtration system, which is pre-loaded with a media that lasts 5-10 years or longer. All you’ll need to do is replace the sediment filter.

US water systems installation

Manufacturer Warranties/ Support

Finally, make sure you’re aware of a well water filter’s warranty before you buy it.

A good warranty tells you that the manufacturer is prepared to offer customer support if their product doesn’t meet expectations.

Look for a whole house filter with a warranty of at least 2 years; ideally up to 10 years. Lifetime warranties are even better.

✅ How to Maintain A Well Water Filter’s Performance

Well filtration systems for wells only work in the long term with routine maintenance.

The main maintenance task is changing the filters. Check the user manual to see how often you should buy new filters for your unit.

📌 Cartridge-based systems usually need their filters changed every 3-12 months. Tank-based systems, like air injection iron filters, have a longer media lifespan – usually 5+ years.

Aside from changing the filters, clean and sanitize the unit once a year, and follow any other specific cleaning instructions in your user manual.

Whole house sediment filter install

✍️ A Note On Water Softeners

Water softeners aren’t classed as water filters because their purpose isn’t to produce filtered water by removing harmful contaminants.

Instead, water softeners use ion exchange to swap hard water minerals with sodium ions.

However, because water softeners are so commonly required as a method of well water treatment, it’s worth being aware of what these units are and how they work.

A water softener uses salt to soften water. The best salt-based water softeners eliminate limescale by completely removing calcium and magnesium from water.

Water softening systems are installed as whole home, point of entry units, like most well water filter units.

❔ How Do Well Water Filters Work? FAQ

What kind of filtration system do you need for well water?

The best kind of filtration system for well water is a whole house system. Whole house filtration systems protect your entire plumbing system, pipes, and appliances from contaminants like heavy metals, organic chemicals, and sediment.

Can you use a reverse osmosis system to filter well water?

Yes, you can use a reverse osmosis system to filter well waterbut RO usually needs pre-filtration when treating well water. Private wells are often higher in hard minerals and sediment, which could clog the RO membrane and reduce its performance abilities and lifespan.

Do water filter pitchers treat well water?

Some water filter pitchers can treat well water, but most aren’t suitable. We still recommend using some form of sediment pre-filtration if you decide to treat your well water with a water filter pitcher, to prevent the pitcher’s filter from becoming quickly clogged.

  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

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