A water filter installed under a kitchen sink.

10 Best Under Sink Water Filters (2021 Reviews)

The quality of your drinking water is one of the most important features of your home. Everyone expects the tap water in their whole house to be high-quality, pure water, clean water. There are many harmful contaminants, impurities, and microorganisms as well as healthy minerals and beneficial minerals to your body. There are many different types of water filters – countertop water filters, whole house water filters – as well as water softeners that can prevent buildup in your pipes.

Whether your water source is from well water or municipal water, your water quality can be much lower than you expect. This is why purified water is important – you can have clean water and rid your water of bad taste. Here is an article by The Guardian detailing the state of clean water in the USA. Water treatment products can be especially important for you and your family, so we have set up this buying guide so you can check which one is best for you. There are also useful links to each product so you can get started today!

In a hurry? Here’s the test winner after 10 hours of research:

Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Price
$134.89
Rating
Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Price
$134.89
Rating

10 Best Under Sink Water Filters (2021 Reviews) – Overview

Here are the top 5 picks (keep scrolling for more details and picks 6-10).

Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Clearly Filtered Triple Stage Kitchen Faucet Filtration System - With 99% Fluoride & Lead Removal (Installs on your primary faucet, no drilling or seperate spigot required)
Waterdrop 15UA Under Sink Water Filter, NSF/ANSI Certified Direct Connect Under Counter Water Filter, 16000 Gallons High Capacity to Reduce Chlorine, 0.01micron, Bad Taste & Odor, USA Tech
CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA
Aquasana 3-Stage Max Flow Claryum Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chloramine - Brushed Nickel - AQ-5300+
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Clearly Filtered Triple Stage Kitchen Faucet Filtration System - With 99% Fluoride & Lead Removal (Installs on your primary faucet, no drilling or seperate spigot required)
Waterdrop 15UA Under Sink Water Filter, NSF/ANSI Certified Direct Connect Under Counter Water Filter, 16000 Gallons High Capacity to Reduce Chlorine, 0.01micron, Bad Taste & Odor, USA Tech
CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA
Aquasana 3-Stage Max Flow Claryum Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chloramine - Brushed Nickel - AQ-5300+
Price
$134.89
Price not available
Price not available
$119.95
$167.99
Rating
-
-
-
-
Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Price
$134.89
Rating
Overview
Clearly Filtered Triple Stage Kitchen Faucet Filtration System - With 99% Fluoride & Lead Removal (Installs on your primary faucet, no drilling or seperate spigot required)
Title
Clearly Filtered Triple Stage Kitchen Faucet Filtration System - With 99% Fluoride & Lead Removal (Installs on your primary faucet, no drilling or seperate spigot required)
Price
Price not available
Rating
-
Overview
Waterdrop 15UA Under Sink Water Filter, NSF/ANSI Certified Direct Connect Under Counter Water Filter, 16000 Gallons High Capacity to Reduce Chlorine, 0.01micron, Bad Taste & Odor, USA Tech
Title
Waterdrop 15UA Under Sink Water Filter, NSF/ANSI Certified Direct Connect Under Counter Water Filter, 16000 Gallons High Capacity to Reduce Chlorine, 0.01micron, Bad Taste & Odor, USA Tech
Price
Price not available
Rating
-
Overview
CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA
Title
CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA
Price
$119.95
Rating
-
Overview
Aquasana 3-Stage Max Flow Claryum Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chloramine - Brushed Nickel - AQ-5300+
Title
Aquasana 3-Stage Max Flow Claryum Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chloramine - Brushed Nickel - AQ-5300+
Price
$167.99
Rating
-

 

1. iSpring CU-A4 4-stage Under Sink Water Filter

iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
377 Reviews
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
  • SUPERIOR PERFORMANCE: The advance 4-stage design, which includes both Ultrafiltration and KDF/GAC stages removes up to 99% of most problematic pollutants such as chlorine and chlorine treatment...

The iSpring CU-A4 4-stage Under Sink Water Filter has a great price-to-quality ratio and can take care of 99% of all contaminants, such as TDS (Total Dissolved Solids) sediment, dirt, heavy metals, pesticides, chloramine, giardia, and arsenic. It has four stages of filtration and it can get through contaminants 0.1-microns in size. It will also help with the smell and taste of your water.

It is both NSF (National Science Foundation) /ANSI (American National Standards Institute) certified. This system can be connected to a fridge and has a 1-year manufacturer’s warranty. The only downsides to this system are that fluoride is not removed, and you do have to have enough room under your sink to fit all 4 cartridges since the product will not work without all 4 cartridges present. Apart from this, it should be an easy enough system to install that you will only have to get replacement filters for every 6-12 months.

 

Features of the iSpring CU-A4 4-stage Under Sink Water Filter:

  • Excellent price-to-quality ratio
  • 4-stage filtration
  • 0.1-micron ultrafilter
  • 99% of all contaminants
  • Sediment, dirt, heavy metals, pesticides, chloramine, and arsenic removed
  • Odorless water
  • Fluoride is not removed
  • NSF/ANSI certified
  • Can be connected to a fridge
  • 1-year manufacturer’s warranty
  • 24/7 customer support
  • Easy installation
  • Snap-on fittings, no tools required
  • The set comes with 4 cartridges and a stainless-steel water faucet
  • You will not need to detach any water lines to get the system in place
  • Replace filters once every 6-12 months

 

2. Clearly Filtered Kitchen Faucet Filtration System

Clearly Filtered Triple Stage Kitchen Faucet Filtration System - With 99% Fluoride & Lead Removal (Installs on your primary faucet, no drilling or seperate spigot required)
  • ✅#1 WATER FILTER: Our one-of-a-kind 3-stage system is capable of removing harmful contaminants from the tap water right from your faucet. It removes more chemicals and contaminants than the top 5...

The Clearly Filtered Kitchen Faucet Filtration System can remove over 220 known contaminants (this includes chlorine and fluoride) and can produce great tasting water as well as odorless water. This system is 100% American-made and both EPA (the United States Environmental Protection Agency) and NSF (National Science Foundation) certified. It has a lifetime warranty from the manufacturer.

You can install this system fairly easily, both horizontally and vertically, and filter life should be around 12 months. You can simply connect it to your existing water lines without the need to purchase a faucet. The only downside to this system is that there is no bypass valve, meaning the system will always be in use, and there is also no light indicator that will let you know when to replace the filter.

 

Features of the Clearly Filtered Kitchen Faucet Filtration System:

  • The filter will last for about 12 months
  • Installation is easy
  • Over 220 contaminants removed
  • Tasteless and odorless water produced
  • EPA and NSF certified
  • 100% American-made
  • No need to purchase a faucet, just connect to the existing water lines
  • No bypass valve, so the filter will be almost always in use
  • No light indicator to prompt you to replace the filter
  • Lifetime warranty from the manufacturer

 

3. Waterdrop 15UA Under Sink Water Filter System

Waterdrop 15UA Under Sink Water Filter, NSF/ANSI Certified Direct Connect Under Counter Water Filter, 16000 Gallons High Capacity to Reduce Chlorine, 0.01micron, Bad Taste & Odor, USA Tech
  • 【Superior material】 With a filtration accuracy of 0.01 μm, the Ultrafiltration membrane filters out impurity larger than 0.01 μm. Activated carbon block and other advanced filter media ensure...

The Waterdrop 15UA Under Sink Water Filter System is an affordable system that boasts a 5-stage filtration within only one cartridge (meaning it is space-saving, while other systems on the market would need around 2-3 cartridges for each stage). It does not require a separate faucet or electricity in order to work.

This product removes heavy metals (lead and mercury), fluoride (through the activated alumina), and 99% of chloramine. The activated carbon block will also make sure your water will taste and smell better. This product has a lifespan of two years (or 16,000 gallons). The only downside to this system is that it cannot be used with hot water and similarly to the product mentioned above, it will not let you know when you need to change the filter.

 

Features of the Waterdrop 15UA Under Sink Water Filter System:

  • Does not require a separate faucet to connect
  • The system does not require electricity
  • Cannot be used with hot water
  • There is no way to track when a filter change is due
  • Fairly affordable
  • Only one cartridge, yet the water filtration happens in 5 stages
  • Removes heavy metals (lead and mercury), fluoride (through the activated alumina), and 99% of chloramine
  • Activated carbon block improves water tastes and smells
  • Lifespan of two years or 16,000 gallons

 

4. CuZn UC-200 Under Counter Water Filter

Sale
CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA
  • Incredible Capacity and Lifespan, Up to 5 Years per Filter; CuZn Backs the UC-200’s Long Lasting Performance With a Comprehensive 5 Year Prorated Performance Warranty, CuZn Will Provide Warranty...

The CuZn UC-200 Under Counter Water Filter is a high-capacity, sturdy system with a simple installation that features no need for an additional faucet since it will connect directly to your sink’s cold water line. You will receive an adjustable wrench and all the components that you need in order to install it. This is a very long-lasting filter that can last you for up to five years or 50,000 gallons of water. The only downside to this system is that you will be unable to get filtered hot water from your tap, so you will need to heat it up in a kettle or pot in order to get clean hot water.

 

Features of the CuZn UC-200 Under Counter Water Filter:

  • Simple Installation
  • No need for an additional faucet
  • Will connect directly to your sink’s cold water line
  • No filtered hot water
  • Only need an adjustable wrench and the components that come with the filter to install
  • The filter is a little larger than other models
  • Long-lasting filter (5 years)
  • Produces 50,000 gallons of filtered water

 

5. Aquasana AQ-5300.55 3-Stage Under Sink Water Filter 

Sale
Aquasana 3-Stage Max Flow Claryum Under Sink Water Filter System - Kitchen Counter Claryum Filtration - Filters 99% Of Chloramine - Brushed Nickel - AQ-5300+
  • Instantly Transform Ordinary Tap Water Into Clean, Extraordinary Water - Removes up to 99% of 77 contaminants while leaving healthy minerals so you can drink with confidence. This system will NOT...

The Aquasana AQ-5300.55 3-Stage Under Sink Water Filter System is a lovely budget-friendly option that will remove chlorine, pesticides, herbicides, heavy metals, and VOCs (Volatile Organic Compounds) from your water. It features a filter change notification which many other models lack as well as the option to personalize the faucet during purchase so that it will match your kitchen’s style and the rest of your fixtures.

It also boasts a twist-off design, meaning that in order to replace the filters (which you will need to do every six months) all you need to do is twist off the old filters and twist the new ones onto them. This process should only take about 5 minutes. The only downside to this system is that the O-rings in this product tend to fail after 2 or 3 years of use.

 

Features of the Aquasana AQ-5300.55 3-Stage Under Sink Water Filter System:

  • Budget-friendly
  • Removes chlorine, pesticides, herbicides, heavy metals, and VOCs
  • Twist-off design – twist off old filters and twist the new one on
  • Change the faucet’s finish during purchase so it will match the rest of your fixtures
  • Filter change notification
  • O-rings will fail after 2 or 3 years of use
  • Filter needs replacing once every 6 months

 

6. APEC WFS-1000 3 Stage Under Sink Water Filter 

APEC WFS-1000 Super Capacity Premium Quality 3 Stage Under-Sink Water Filter System
  • High quality, designed, engineered and assembled in the USA; System built with US MADE super capacity filters for long lasting dependable filtration

The APEC WFS-1000 3 Stage Under-Sink Water Filter System features a 3-stage filtration process that comes with great water pressure, which other products on the market sometimes do not do. The faucet comes with stylish stainless steel construction. This is a very easy product to install, even coming with pre-drilled holes so you can mount it on the wall if you would like. It comes with all of the equipment you will need for the installation to go smoothly and easily. The only downside to this system is that you will have to add a new faucet (which you will also receive when you purchase this product) since it cannot be connected directly to your existing faucet.

 

Features of the APEC WFS-1000 3 Stage Under-Sink Water Filter System:

  • 3-stage filtration process
  • Ease of installation
  • Comes with all the equipment you need for the installation
  • Comes with pre-drilled holes so you can mount it on the wall
  • Good water pressure
  • Faucet has a stainless steel construction

 

7. Frizzlife Under Sink Water Filter System

Sale
Frizzlife Under Sink Water Filter System-NSF/ANSI 53&42 Certified High Capacity Direct Connect Under Counter Drinking Water Filtration System-0.5 Micron Removes 99.99% Lead, Chlorine, Bad Taste & Odor
  • [Two-stage Advanced Water Purifier With 0.5 Micron]: The Frizzlife MK99 Water Filtration System includes a TWO-STAGE High precise compound filter, which has a unique technology that removes over...

The Frizzlife Under Sink Water Filter System can remove 99, 99% of water contaminants such as lead, fluoride, arsenic, copper, VOCs, cyst, and chlorine and particles the size of 0,5 microns. The most significant feature of this system is that it will also make sure that the minerals you do want staying in your water will remain there (this process is called remineralization).

This system is very easy to install and it should only take you around 3 minutes to do so, without the need for a plumber. You also eliminate the need for shutting off the water supply when changing the filter. This system is also eco-friendly and it will not make you lose the water flow.

 

Features of the Frizzlife Under Sink Water Filter System:

  • Removes 99, 99% of water contaminants such as lead, fluoride, arsenic, copper, VOCs, cyst, and chlorine
  • Removes particles as small as 0, 5 microns
  • Makes sure that the useful minerals stay in the water
  • Installation of this unit is very easy (DIY possible)
  • It will only take 3 minutes to mount this system
  • You will not have to pay a plumber to install it 
  • No need to shut off the water supply when changing the filter
  • Does not reduce the water flow
  • Eco-friendly as there is no need to throw away the whole plastic filter cartridge when replacing the filter
  • The filter is compatible with both ½ inch and 3/8 inch water valves

 

8. Doulton W9330958 SuperCarb Under Sink Water Filter

Doulton W9330958 SuperCarb Under Sink Filter System
  • Doulton W9330958 Under Sink Filter System is an Acetal/Polyester In-Line System complete with Installation Kit with 3/8-Inch Push-fit connectors

The Doulton W9330958 SuperCarb Under Sink Filter System is a four-stage filtration system that is exceptionally durable due to its solid housing and thick tubing. The first stage of filtration goes through a carbon block filter, meaning it will remove particles in your water such as bacteria and parasitic cysts, as well as bad smells or tastes in your water. The second has antibacterial properties and is self-sterilizing, so you can make sure it will not become contaminated.

The third filter is also a carbon filter that removes chlorine and organic compounds. The fourth stage is a sediment filter that reduces heavy metals in your water. The only downside to this system is that at the point of purchase, you will not receive all the parts needed for the installation of this product. You will have to seek these components separately, thus spending more time than normal on the installation of this filter.

 

Features of the Doulton W9330958 SuperCarb Under Sink Filter System:

  • 4-stage filtration
  • Durable
  • The filter has a solid housing and thick tubing
  • Not all the parts needed for the installation are included in the box

 

9. Woder WD-S-5K Under Sink Water Filter

Woder WD-S-5K Under Sink Water Filter with Direct Connect Fittings - WQA Certified – USA Made - Ultra High Capacity - Removes Chlorine, Lead, Chromium 6, Heavy Metals and Contaminants
  • WQA GOLD SEAL CERTIFIED to NSF/ANSI 42 for Chlorine, taste, odor and NSF/ANSI 372 for lead free compliance as verified and substantiated by test data. The Woder WD-4K with DC fittings removes lead,...

The Woder WD-S-5K Under Sink Water Filter will remove lead, heavy metals, chlorine (99%), chromium 6, mercury, carcinogens, and other contaminants (99%). It will also remove turbidity (cloudiness or haziness in your water) as well as unpleasant odors and tastes. It is 100% American-made and WQA Gold Seal certified to NSF/ANSI 42 for chlorine, taste, odor, and NSF/ANSI 372 for lead-free. This is an easy-to-install, no-plumbing-needed system that will last you for 5,000 gallons, which can be considerably less than other brands on the market. Its flow rate stands at 2 GPM (gallons per minute) at 65 psig (pounds per square in gauge).

 

Features of the Woder WD-S-5K Under Sink Water Filter:

  • WQA Gold Seal certified to NSF/ANSI 42 for chlorine, taste, odor and NSF/ANSI 372 for lead-free
  • Made in the USA
  • No plumbing required
  • Hoses fit standard 3/8” water valves under US kitchen and bathroom sinks
  • Lasts for 5,000 Gallons
  • Flow rate is 2 GPM at 65 psig

 

10. Filtrete Advanced Under Sink Water Filtration System 

Sale
Filtrete Advanced Under Sink Quick Change Water Filtration System 3US-PS01
  • HEALTHY LIVING FILTRATION LEVEL - This system reduces chlorine taste & odor as well as microbial cysts

The Filtrete Advanced Undersink Water Filtration System is the cheapest model on this list that can remove up to 99.99% of the sediments, soils, sand, and cysts in your water as well as up to 96.6% of the odors and tastes. It will filter up to 10,000 gallons of water. This system will connect directly to your cold water line, eliminating the need for a separate faucet for filtered water. This is a very easy-to-install filter that should only take you about 30 minutes for the whole installation process. The only downside to this system is that although the manufacturer claims it will last you a whole 6 months, reviewers have said that it actually only lasts around 4 months maximum.

 

Features of the Filtrete Advanced Undersink Water Filtration System:

  • Cheapest model
  • Does not come with a separate faucet for the filtered water
  • Connects directly to your cold water line
  • Installing this model is easy
  • The installation process should not take more than 30 minutes
  • Can filter up to 10,000 gallons of water (manufacturer claims it lasts 6 months)
  • Removes up to 99.99% of the sediments, soils, sand, and cysts in your water
  • Removes up to 96.6% of the odors and tastes

 

Our Winner:

Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Price
$134.89
Rating
Overview
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Title
iSpring CU-A4 4-Stage 0.01 micron High Capacity Premium Under Sink Drinking Water System, Tankless, Quick Filter Change, Chrome Faucet, White
Price
$134.89
Rating

The iSpring CU-A4 4-stage Under Sink Water Filter is the absolute best product on this list. It has the best price-to-quality ratio, can remove 99% of all contaminants, and is certified to both NSF and ANSI standards. It is without a doubt the best under sink water filter out there.

 

Final Thoughts

 

Under-sink drinking water filters are water filters that you can place under your kitchen sink that take water from your cold water pipe and send it through a plastic tube into your filter. Then, the purified water will come through either your own kitchen faucet or one that is provided for you. Since this process happens on demand there is no wastewater produced as with other types of systems. Here is an article by Remodelista explaining the benefits of an undersink water filter. They can be a fantastic way to produce purified, clean water without the hassle that comes with other systems. The only downside is that you are only able to get purified water for your kitchen, not for the entire home, but other than that, it can be a great way for you to provide great water for you and your family.

 

Bonus tip: Check out this fun, quirky video by Good Mythical Morning where they put weird things through water filters to see how they work!

 

 

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Joshua Perkins

Joshua spent ten years as a water systems technician in California before settling down with his wife and two young children in Nashville in 2018. Through all of his experience, he learned the benefits and shortfalls of so many different types of water filtration systems, from pitchers to whole-house installations. He started Water Filter Authority in 2019 to empower other families to make the right decision for their long-term health and wellness.