Whole House Water Filter vs Under Sink Filter Systems

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Wondering whether an under-sink water filter or a whole house water filter is better suited to you? Keen to learn the differences between these filters, and learn which, if any, is the best choice?

You’ll find all the information you need to know in this guide. By the end, you should be well informed enough to decide on one of these filter types for your home.

🚰 What Is a Whole House Water Filter?

A whole home water filter is a series of filters within a single filtration system. Why is this filtration system known as “whole house”? Because it’s installed at your water’s point of entry (where your main water pipe enters your home), upstream of your hot water heater.

Whole House Water Filter Benefits

The key benefits of a whole house water filter system are:

  • Thorough filtration
  • Prevents damage to your whole home’s plumbing and appliances
  • Filters drinking water and shower water, preventing skin and hair problems
  • Dedicated systems for city and well water
Springwell CF whole house filtration system

Whole House Water Filter Setbacks

The disadvantages of whole house filters are:

  • Require a more permanent installation; not suitable for rentals
  • May need a professional to install
  • More expensive option

πŸ“₯ What Is an Under-Sink Water Filter?

An under-sink water filter is essentially the same: it’s also a series of filters within a single filtration system. However, as the name suggests, under-sink water filters are installed at the cold water line underneath your kitchen sink.

Under-The-Sink Water Filter Benefits

The key benefits of an under-the-sink filter are:

  • Affordable filtration method
  • Easy to install and maintain
  • Good for rentals – doesn’t require permanent changes to plumbing
  • Space-saving
clearly filtered under sink direct connect system

Under-The-Sink Water Filter Setbacks

Some of the setbacks of an under-the-sink filter are:

  • Has no effect on the water in your showers or appliances
  • More frequent maintenance required
  • May reduce your water flow rate

πŸ“ The Key Difference Between Whole House Filters and Under-Sink Filters

The key difference between whole house water filters and under-sink filter systems is location.

A whole house system delivers filtered water around your whole home. Because it’s installed upstream of your water heater, it allows for both hot and cold water to be filtered.

All the water used in your plumbing and appliances, from your showers to your dishwashers and washing machines, is filtered by a whole house filtration system.

Under-the-sink water filters deliver filtered water to your cold water kitchen faucet. These filters are only designed to filter tap water for drinking.

When you install an under-sink water filter, the purpose is to filter your drinking water. Your entire home’s plumbing and appliances won’t be protected by this type of filter.

whole home water filter vs under-sink filter

πŸ†š Under-Sink Water Filter vs Whole House Water Filter Comparison

Let’s compare some of the key features of a whole house filter and under-sink filter system.

Cost & Value for Money

Which is more affordable, a whole house water filter or an under-sink filtration system?

System TypeInitial Cost
Whole Home$500-$10,000
Under Sink$100-$500

Under-sink water filters are smaller and deliver more targeted filtration than whole house water filtration systems, so they’re the more affordable option.

You can expect to spend $100-$500 on an under-the-sink filtration system, depending on the type of filtration provided.

Whole house systems cost much more – they usually start at $500 and can cost way beyond $2,000 if they offer specialist filtration.

Which filter system is the best value for money? They’re actually pretty even. Although whole house filtration systems cost so much more, they offer so much more. You’ll likely think the extra investment for a whole house system worthwhile if you want the perks of filtering your entire home’s water supply.


Are whole house water filters or under-sink filters the biggest units?

Unsurprisingly, whole house water filtration systems are about twice the size of under-the-sink units. Whole home filters have the biggest cartridges because they need to treat a larger volume of water on a daily basis without reducing flow rate.

Regardless of the system type you choose, manufacturers know that customers don’t want a filtration system that takes up loads of space. Most filter systems are compact units, combining several filter cartridges into a confined housing unit, or several filter stages into a single tank.

Some systems have the potential to be bigger than others. For instance, under-sink reverse osmosis filters with a water storage tank take up much more room than tankless systems.

Taking measurements for whole house water filter install

Type of Filter

What types of filters are on offer in whole house and under-sink systems?

A whole house filtration system typically combines carbon media with other types of media, like KDF, ion exchange, and activated alumina. This media is either used in a cartridge-based system or a tank-based unit, and is protected by a sediment filter.

Other types of whole house water filters are air injection filters (which treat well water containing iron, sulfur, and manganese) and reverse osmosis systems, although whole-house RO is still pretty rare.

A typical under-sink filter has a very similar design to a whole-house water filter, combining several different filter media to remove common tap water contaminants.

Reverse osmosis filters are much more commonly installed as under-the-sink, point of use filters than whole home filters. The RO filtration method is incredibly effective, but wastes water, so it’s not typically an efficient option for whole-home use.

Contaminant Removal Abilities

Which filter can remove more contaminants, an under-the-sink filter or a whole home filter?

Both types of water filter system are capable of removing the same contaminants, including:

  • Chlorine
  • Chloramine
  • Volatile organic compounds
  • Heavy metals
  • Pesticides
  • Herbicides
  • Chemicals
  • Fluoride
  • Arsenic
  • Nitrate

Of course, not all filters can remove all of these contaminants. The quality of the filter, and the type of filter media used, effects its contaminant removal abilities. Some filters (like RO units) can remove more contaminants than those listed above, including bacteria and minerals.

However, because under-the-sink filters typically use smaller versions of the cartridges used in whole-home filters, they serve virtually the same purpose when it comes to contaminant removal.

impurities found in drinking water

Maintenance Requirements

Do under-the-sink or whole home filtered water systems require the most maintenance?

Again, this depends on the filter type. Generally, though, whole house filter cartridges last longer than under-the-sink cartridges.

Changing filter cartridges in a whole house system is typically a once-yearly job.

Under-the-sink units typically need to be replaced every six months or so.

Some whole home filtration systems use a tank containing media that’s designed to last up to five years or beyond before it needs replacing, reducing the frequency of maintenance. Under-the-sink tank-based systems aren’t available.

Intended Purpose

An under-sink filter is a point of use system. This means it’s intended to treat water that comes out of one specific faucet. People who just want to filter water for drinking will enjoy what an under-the-sink, point of use filter can offer.

A whole house filter is a point of entry system. This means it’s intended to improve water quality around your entire home, rather than only focusing on drinking water. If you want clean water for showering and bathing, washing dishes, doing your laundry, and drinking, a whole house filter should appeal to you.

Before and after installation of whole house water filter Sytem

πŸ‘¨β€βš–οΈ Which is Best: Whole House Water Filters or Under-Sink Filters?

Wondering whether an under-the-sink filtration system or a whole home filter is the best choice? Ultimately, these two systems both have a lot to offer, and the best system for you depends on your needs and preferences.

  1. Do you prefer to spend a bit less on a filter that removes unpleasant tastes and improves your drinking water quality? If so, consider an under-the-sink system.
  2. Or would you rather spend more money on a system that can remove contaminants from your entire home’s water supply? If so, a whole house water filter is probably your preferred choice.

When deciding on the right system for you, consider your budget, your water usage, your maintenance preferences, your water quality, and your reasons for wanting to invest in a water filtration system. This should help you to come to a conclusion.

🧠 Whole House Filter Vs Under Sink Filter FAQs

Are under the sink water filters worth it?

Yes, under-the-sink water filters are worth it – as long as your intended goal is to remove contaminants like chlorine and heavy metals from your drinking water only. Focus your search on highly-reviewed under-sink filters that are sold by a reputable manufacturer to make sure your investment is worthwhile.

Is a whole house water filtration system worth it?

Yes, a whole house water filter system is worth it – as long as your goal is to remove contaminants from your whole home’s water supply. Do your research and shop around for a capable whole home system that won’t affect your water pressure.

What other types of filters are available?

Aside from under-the-sink and whole home filters, there are a few smaller or more portable point of use options, like faucet-mounted filters, water filter pitchers and dispensers, and countertop gravity filters.

  • Laura Shallcross
    Senior Editor

    Laura is a passionate residential water treatment journalist who holds an undergraduate degree in Print Journalism and a master’s degree in Creative Writing. Over a span of 5 years she's written on a range of topics including water softening, well water treatment, and purification processes.

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