Best Under Sink Water Filter | Reviews & Buyer Guide 2020

It is expected that when you drink water from the tap in your home that you are getting clean water and that it’s safe.

Until recently, drinking water from that flows freely into your home has been a privilege that most enjoy without having to worry about consequences. However, that isn’t the case anymore.

Now, you cannot be sure that what you're drinking from your home is going to be clean and healthy.

The bad news about your home tap water is that it has the potential to come with contaminants that can cause real health issues.

The good news is, under sink filtration systems are becoming more popular - they provide you with cleaner water that is safe for the whole family. The main reason for their popularity is that they are easier to install than other filtration systems, and they do not produce wastewater the way other systems would. 

We’ve done the research to help you find the best under sink water filter system this 2020 for your home, with help of this useful buying guide.

In a Rush?

Overall: iSpring RCC7AK Reverse Osmosis

FEATURES

  • 6-Stage Alkaline Remineralization Layered Filtration
  • Removes Up To 99% Of Over 1,000 Harmful Contaminants
  • Beautiful European-Style Kitchen Faucet
  • DIY Installation

Top Choices on the Market

Product

Description

Price

iSpring RCC7
  • 6-Stage Filtration System
  • Reverse Osmosis Technology
  • Alkaline Remineralization
CuZn UC-200
  • Superior Filtration System
  • Filter Capacity: 50,000 Gal or 5 Years
  • 5-Year Warranty
Woder 10K
  • Selective Filtration Technology
  • Filter Capacity: 10,000 Gal or 3 Years
  • 99.9% Contaminant Removal Power
Culligan
  • Twist On, Twist Off Mechanism
  • Filter Life Indicator
  • 2-Year Limited Warranty
Aquasana AQ-5300
  • Claryum Selective Filtration Technology
  • Filter Capacity: 800 Gallons
  • 1-Year Warranty
Whirlpool
  • EZ-Change Light Indicators
  • 6 Months Filter Life
  • 1-Year Factory Warranty
3M Aqua-Pure
  • 3-Stage Carbon Block Filtration
  • Sanitary Quick Change
  • Filter Life: 6,000 Gallons or 1 Year
GE
  • Twist and Lock System
  • Dual Flow Filtration Technology
  • LED Filter Life Indicator
APEC WFS-1000
  • 3-Stage Carbon Block Filtration
  • Filter Last for 1 Year Usage
  • Built with US Made Super Capacity Filter
Frizzlife
  • 2-in-1 Advanced Composite Filtration
  • Filter Last for 2 Years Usage
  • Auto Shut-Off Design
Filtrete
  • Filtrete Maximum Filtration
  • Filter Last for 6 Months Usage
  • NSF Certified and Tested

11 Best Under Sink Water Filter Reviews (Updated 2020)

1. iSpring RCC7AK 6-Stage Superb Taste High Capacity Under Sink Reverse Osmosis Drinking Water Filter System with Alkaline Remineralization-Natural pH, White

iSpring RCC7AK 6-Stage Superb Taste High Capacity Drinking Water Filter System with Alkaline Remineralization-Natural pH

This under-sink water filter system comes with a multi-stage filtration technology that is also remineralization and has passed many rigorous tests to prove that it’s among the best under skin filtration systems in today's market.

The 5-stage filter ensures that the water you get will be significantly purified. This filter is so good it does not remove only contaminants but necessary minerals.

For this reason, the remineralization of Ca+ and Mg+ are reintroduced and provides you the water that you are seeking when you go for a clenching glass.

FEATURES

  • Capacity Of 75gal Per Day
  • Easy Installation, With Design That Fits Perfectly Under A Standard Kitchen Sink
  • Alkaline Remineralization Restores Minerals And Makes A Balanced Alkalinity Which Is Beneficial To Health
  • 6-Stage Filtration 
  • Removes Almost 99% Of Over A Thousand Contaminants

Filter Life: 

up to 2-3 years of Usage

Filtration Technology: 

Reverse Osmosis with Alkaline Remineralization

Pros

  • Comes with a lead-free brass faucet
  • It is affordable
  • Removes up to 98% of contaminants
  • Easy installation

Cons

  • The unit is heavy
  • It does impact your flow rate slightly

All in all, this  is a great choice - while it’s heavy and takes a bit of time to install, the installation process is actually quote simple. Once set and you allow for the specialized time of water flow, you will experience clean and clear water that will have lower TDS than some bottled water you can buy.

2. CuZn UC-200 Under Counter Water Filter - 50K Ultra High Capacity - Made in USA

CuZn UC-200 - 50K Ultra High Capacity - Made in USA

This under-sink water filter system is a top-rated product because it doesn’t need additional faucets and it’s incredibly easy to install. You will notice immediate the quality improvements on the taste and odor. The design is simple and compact. You need only five minutes of your time to install this as it connects quickly to your cold water line.

FEATURES

  • Filter Capacity Of 50,000 Gal
  • Hassle-Free Installation Process
  • Superb Purification Without Removing Its Minerals Beneficial For Health
  • Made In USA

Filter Life: 

up to 5 years of Usage

Filtration Technology: 

Bacteriostatic Filtration System

Pros

  • Noticeably reduces contaminants
  • Helps make water tastier
  • Easy to install
  • Does not reduce flow rate
  • Comes with a five-year pro-rated warranty

Cons

  • This unit was not designed to remove TDS (Total Dissolved Solids)

If you are wanting a top-rated water filter system that fits under your sink and can be installed in minimal time, the CuZu UC-200 Under Sink Water Filter is the one you want to get. From the sleek, simple design to the result of better water quality makes this filter system the one of the best in the market.

3. Woder WD-S-8K-DC Water Filtration System - WQA Certified – USA Made Ultra High Capacity Direct Connect Under Sink Water Filter - Removes Chlorine, Lead, Chromium 6, Heavy Metals, Odors/Contaminants

Woder WD-S-8K-DC Water Filtration System - WQA Certified – USA Made Ultra High Capacity Direct Connect - Removes Chlorine, Lead, Chromium 6, Heavy Metals, Odors/Contaminants

This filtration system is very effective, considering its relatively lower price compared to other models.

The installation is as simple, as everything you will need comes with the system. The filters rarely need to be changed as they are good for up to three years. So it’s pretty easy to get healthy, clean water for your family to enjoy in a few easy steps!

FEATURES

  • Capacity Of 10000 Gal Of Usage
  • Crystal Clear Safe And Better-Tasting Water On Every Drop
  • Removes Impurities And Contaminants While Retaining All The Healthy Minerals
  • Ready-To-Use In Five Minutes

Filter Life

up to 3 years of Usage

Filtration Technology: 

Selective Filtration

Pros

  • Long-lasting filters
  • Easy installation
  • Good price
  • Remove the majority of contaminants

Cons

  • Slowed water pressure
  • Installation is a bit more difficult for those with older homes

When looking for a good budget water filtration system that you can easily hide under your sink, then the WODER 10k-Gen3 is the ideal under sink filter. Installation is simple unless you have an older home, and the filters last up to three years, which is a considerable amount of time comparably. Most importantly, you get clean water that tastes good and is mostly free from contaminants.

4. Culligan US 4 EZ-Change Sink with Dedicated Faucet and Premium Filter

Culligan US 4 EZ-Change with Dedicated Faucet and Premium

This under-sink filtration system includes a faucet meant to be used with it. The filter cartridge itself is easy to change and the entire unit is easy to install.

You can quickly install fitting with a quick twist on and off. Using this filter, you can reduce the smell of odors, remove most contaminants, and enjoy clean and clear water.

FEATURES

  • Turns Tap Water Into Great-Tasting And Safe To Drink
  • Easy Fitting With Installation Hardware Included
  • Easier To Know When To Change Filter With The Aid Of LED Filter Life Indicator
  • 2-Year Limited Warranty

Filter Life: 

up to 6 months of Usage

Filtration Technology: 

Twist on/off filter mechanism

Pros

  • Filters are easy to change and inexpensive
  • Replacement parts will not make a big dent in your wallet
  • Removes up to 98% of all contaminants
  • Simple installation

Cons

  • The plastic parts aren’t all that durable
  • You may need additional parts for installation than what is provided

For an inexpensive and effective under sink water filter, the Culligan US is the one you want. You will have clean and clear water that is free from contaminants and that tastes delicious. As a huge plus, you won’t have to spend a great deal of time installing this unit.

5. Aquasana AQ-5300+.55 3-Stage Max Flow

Aquasana AQ-5300+.55 3-Stage Max Flow

The Aquasana helps to transform nasty tap water into clean water that is 99% cleaner than before. This unit is both cost-efficient and long-lasting, as it will filter your water for less than 10 cents a gallon.

Its filters are inexpensive to purchase and simple to change. This unit is designed with only top quality parts for a filtration system you can enjoy for years.

FEATURES

  • Designed For Easy Fitting And Engineered For Simple Filter Replacement
  • Preserves The Minerals Like Calcium, Potassium, And Magnesium Beneficial To Health While Filtering Contaminants
  • Reduces Contaminants Of 77 Kinds Up To 99%
  • 1-Year Warranty And 90-Day Guarantee

Filter Life: 

up to 800 gal of water Usage

Filtration Technology: 

Claryum Selective

Pros

  • Great tasting water
  • Filters out 99% of water contaminants
  • Installing is very simple with clear instructions
  • Excellent customer support

Cons

  • The Bluetooth feature is more of a gimmick
  • Your water flow rate will slow down

This filter system works and does a great job of cleaning your water. You will be able to enjoy crisp water once you get it out of the faucet as it does slow the flow rate. However, installation is a breeze, and if you have any issues, the Aquasana customer service will save the day.

6. Whirlpool WHAROS5 Reverse Osmosis (RO) Water Filtration System With Chrome Faucet, Extra Long Life, Easy To Replace UltraEase Filter Cartridges

Whirlpool WHAROS5 With Chrome Faucet, Extra Long Life, Easy To Replace UltraEase Filter Cartridges

Using an advanced reverse osmosis system, the Whirlpool WHAROS5 will provide you with safer water. Remove up to 15 contaminants from your home and get fresher water that is odor-free and tastes much better. There is an indicator light that lets you know when the filter needs to be changed, and you can do so in seconds without turning off your water. Furthermore, this system is easy to install.

FEATURES

  • Reduces Contaminants Like Chlorine, Lead, Microbial Cyst, And Other Harmful Contaminants
  • Easier Installation And Filter Replacement
  • EZ-Change Indicator Light Alerts You When To Change Filter
  • 1-Year Factory Warranty
  • Proudly Designed And Made In USA

Filter Life: 

up to 6 months of water Usage

Filtration Technology: 

Reverse Osmosis (RO)

Pros

  • Easy to install Under Sink Filter
  • Faucet is modern and contemporary
  • LED indicator light when the filter needs changing
  • Simple filter change

Cons

  • Parts are all plastic
  • Impacts water flow rate

Using this under-sink water filter system, you will get clean and clear water that is delicious and free from contaminants. The only real issue you may experience with this unit is the hookup parts are plastic, and you may want to change them out for brass. However, the system  is easy to install, and the modern faucet will suit most households. Overall, a good unit for any home.

7. 3MFF100, Sanitary Quick Change, Reduces Particulates, Chlorine Taste and Odor, Cysts, Lead, Select VOCs

 3MFF100, Sanitary Quick Change, Reduces Particulates, Chlorine Taste and Odor, Cysts, Lead, Select VOCs

Having an under-sink filter system like this one gives you cleaner water than you have ever had. The installation is a breeze, and changing the filters is quick and easy without having to turn off the water using the built-in shut-off.

 Using this filtration system allows you to have almost full flow as the water passes through the triple stage filtration process that gives you clearer and tastier water that is free from odors.

FEATURES

  • Up To 6000 Gal Capacity
  • Built-In Shut-Off Valve For Easier Filter Replacement
  • Universal System Design Allows Use For Municipal And Well Water Sources
  • Reduces Particulates Like Lead And Parasitic Protozoans And Improves Taste Of Water

Filter Life: 

up to 12 months of water Usage

Filtration Technology: 

3-Stage Carbon-Block Filtration

Pros

  • Easy installation
  • Built-in shut off for filter changes
  • Excellent water taste
  • Removes up to 98% of contaminants

Cons

  • Having to purchase fittings versus water lines that are already crimped
  • The instructions for installation are more complicated than the installation itself

The 3M Aqua-Pure under sink water filter is an excellent choice for most households. Seeing as the only real issue is with installation parts, this product is among the top. You will love how excellent the water tastes and how easy it is to conduct filter changes. When looking for an under sink filter that does not impact your water flow significantly, this is the one you want.

8. GE GXK285JBL Twist And Lock Under Counter Dual Flow

GE GXK285JBL Twist And Lock Under Counter Dual Flow

This water filter is an NSF certified unit that will reduce up to 14 contaminants that you will find in your home water.It will also reduce up to 97% of the chlorine in your drinking water.

The filter is good for about 300 gallons before needing to be changed. You will have cleaner water, and that is tastier and free from odors. Moreover, the twist and lock design helps provide easy filter changes along with easy installation.

FEATURES

  • Up To 300 Gal Capacity
  • Components Made From Engineered Carbon For Ensured High Reliability
  • Easy Installation And Replacement With Twist And Lock Style
  • 1-Year Limited Warranty
  • With LED Filter Life Indicator

Filter Life: 

up to 6 months of water Usage

Filtration Technology: 

Dual Flow System

Pros

  • Easy to install
  • Good flow rate
  • Removes up to 98% of contaminants
  • Filter changing is easy

Cons

  • You need to purchase brass fittings to replace the plastic ones
  • The control knob is plastic and costs upward of $50 for replacement

The GE GXK285JBL under sink filter is a good choice for anyone wanting to have clean and clear water. By reducing the majority of contaminants as well as chlorine, you know you are getting safe water for cooking and consumption. The unit is easy to install and provides a good water flow rate as compared to others.

9. APEC WFS-1000 Super Capacity Premium Quality 3 Stage Under-Sink Water Filter System

PEC WFS-1000 Super Capacity Premium Quality 3 Stage

The APEC WFS-1000 under sink water filter offers three stages of filtration for cleaner, tastier water. It nixes chlorine and other smells and flavors, so you get fresher water without investing a whole lot. At the same time, the filters don’t entirely block healthy minerals from passing through, so your water retains its alkalinity.

FEATURES

  • Built With US MADE Super Capacity Filter
  • Includes 100% Lead-Free Chrome Faucet
  • Removes Chlorine Which Greatly Improves The Taste And Odor Of The Water

Filter Life: 

up to 1 Year of water Usage

Filtration Technology: 

3-Stage Carbon Block Filtration

Pros

  • Removes chlorine and other unwanted smells and tastes
  • Comes with a faucet for seamless installation
  • Features a one-year guarantee and lifetime support

Cons

  • Not designed for TDS (total dissolved solids) removal
  • Can be challenging to adapt if you don’t use the included faucet
  • The third-stage filter is only 5 microns—which still allows many particles to pass through

While the APEC system won’t remove dissolved solids, it does an excellent job of improving the taste of city and well water that’s otherwise safe to drink. Three-stage filtration doesn’t waste water, so you don’t pay more on your bill. There’s no power or water tank necessary, and the water flows as soon as you turn on the sink.

10. Frizzlife Under Sink Water Filter System-High Capacity Direct Connect Under Counter Drinking Water Filtration System-0.5 Micron Quick Change Removes 99.99% Lead, Chlorine, Bad Taste & Odor

Frizzlife High Capacity Direct Connect 0.5 Micron Quick Change Removes 99.99% Lead, Chlorine, Bad Taste & Odor.

If you’re short on space—even under the sink—Frizzlife’s under sink filter is a great space-saving option. It’s a single canister with two-stage filtration that removes lead, heavy metals, chlorine, and more. Each filter will last up to 1600 gallons of water, too, which can give some households clean H2O for up to two years.

FEATURES

  • Greatly Reduces Harmful Chemicals Present In Water By 99.9%
  • Auto Shut-Off Design For Easy Cartridge Replacement
  • Keeps The Minerals Beneficial To Health

Filter Life: 

up to 2 Year of water Usage

Filtration Technology: 

2-in-1 Advanced Composite Filtration

Pros

  • Installs quickly—and the connection lines are included
  • Built-in shutoff valve so you can change filters easily
  • Filters can last up to two years, depending on water consumption

Cons

  • Doesn’t work for TDS—so not a viable option if you have hard water
  • Can be tough to find replacement filters—though they are affordable
  • Some installations require adapters

Installation is straightforward on standard equipment, and the direct connection hoses are included with the unit. Since it’s only a single canister, you can even place it on your countertop for easier installation. The only pitfall is that it won’t clean up severely contaminated water—but that’s also the case with many other single-cartridge units.

11. Filtrete 3US-MAX-S01 Maximum Under Sink Water Filtration System

Filtrete 3US-MAX-S01 Maximum

Another single-canister filter system with a narrow profile, Filtrete’s under sink option removes lead, microbial cysts, and chlorine taste from your water. It filters down to .5 microns to get rid of sediment and rust, too. Each filter lasts around six months, and installation should be snappy in most cases.

FEATURES

  • NSF Certified And Tested
  • Guaranteed Great Tasting And Odorless Water
  • Eliminates 99.9% Of Microbial Cysts, Lead, And Chlorine While Retaning All The Minerals In The Water

Filter Life: 

up to 6 Months of water Usage

Filtration Technology: 

Filtrete Maximum Filtration

Pros

  • Interchangeable filtration options mean you can customize the level of cleaning in your water
  • Relatively quick to install
  • Takes up very little space under the counter

Cons

  • Filters seem to fail sooner than the six-month timeline noted by the manufacturer
  • Not for dissolved solids—leaves lots of minerals in your water
  • Some modifications may be necessary for installation in certain scenarios

Each filter type (Advanced, Maximum, and Standard) works with the system, so you can change up filters. Depending on the results you get with your home’s water, you might choose a heavier-duty filter. This may be an excellent option if you’re looking for a budget solution to gross-tasting tap H2O. Plus, consumers might appreciate that it comes from a notable and reliable brand—3M.

Final Verdict

iSpring RCC7AK

Under sink water filters are ideal for any household. You want to get the best one for your money so that you are not going to have to deal with a slew of problems.

The top choice you can purchase is the iSpring RCC7AK 6-Stage. This unit barely affects your water pressure, and it provides crystal clear water that is safe for drinking. 

With so many issues with residential water arising in recent years, it is in your best interest to invest in an under sink water filter. The top-rated under sink water filters will clean out up to 99% or more contaminants, which ensures good water quality. You don’t want to wait, start enjoying safe water today.


How to Pick the Perfect One For Your Needs

Knowing which are the top-rated under sink water filters is one thing, picking the right one for you is another. Have a look at some key things to look for when choosing your under sink water filter.

Features to Look For

Water Pressure – With all water filters, the pressure of the water is important. Getting a water filter that is capable of giving you decent water pressure is important so that you aren’t waiting forever for a glass of water.

Filtering – Some filters might be more efficient than others, depending on their components. A kit will show you which contaminants are higher in your home water source, and you can use this information to pick the right under sink water filter.

Ease of Installation and Filter Changes – Another important feature to look for is how easy the unit will be to install and, likewise, how easy are the filters to change. If you are not a licensed plumber, you want to be sure that you choose a unit that anyone can install. Furthermore, filter changes that take less than 10 minutes are ideal.

Considerations

Along with the features, there are a few things you want to consider before purchasing an under sink water filter.

You are alright with the filtered water only coming from one source and not through your entire home water system.

  • Decide whether whole-house or single-sink filtration is what your household needs.
  • Determine your average monthly water usage to figure out how often you’ll need to change the filters.
  • Think about how often you’ll need to change the filters, and the overall capacity of the system.
  • Consider your current water quality and decide on an appropriate level and type of filtration.
  • Choose from a single-cartridge filter or a multi-cartridge style, depending on water content and preferences.
  • Think about whether you’ll keep your existing faucet, use the supplied one that comes with your kit (if applicable), or if you want to select a new model to use with your filter.
  • Make sure you have the space under your sink to fit the system you want to buy. Creating a template can help with placement and installation.
  • Determine whether you need filtered water for washing dishes. If not, think about an alternative to under sink systems—like a faucet filter—that you can easily turn off and on for dishwashing and other tasks.
  • Set a realistic budget—and factor in the cost of replacement filters based on an estimate of your household’s water usage.
  • Figure out your home’s plumbing system PSI to compare to manufacturer guidelines. If your PSI is too low, some units may not work properly.
  • Decide if you want extra features, like automatic updates when your filters need to be changed.
  • Figure out whether you want your system to be permanent—if you own your home—or semi-permanent if you plan to move or leave a rental.
  • Choose whether you want a new faucet with your system, or if you’d prefer to buy a cartridge-only system without the additional equipment. Then, you can shop for only the systems that are right for your needs.
  • Investigate whether replacing cartridges will be a big task. You may need tools, or you may need strong grip strength to handle replacing some filters. Consider this before buying a system that might prove difficult to work with later.
  • Decide if you want a warranty on your system, and what type of coverage will be most helpful if something goes wrong. Many brands offer limited warranties that cover specific defects. Some offer money-back guarantees.
  • If you have hard water, read manufacturer specifications carefully. Many systems are not equipped to handle hard water minerals—which means you may need another system entirely, or additional filtration before your under sink system can do its job.

The amount of space you have under your sink is another consideration. If that space is limited, do you have basement access?

You live in an area that is prone to contaminated water or has poor water quality leading to your home. Does your water smell of chlorine or look cloudy at times?

Does your sink allow for an extra faucet, or can you replace an existing one?


Benefits at Home

There are many benefits of an under sink water filtration system. Of course, the biggest benefit is having fresh water that’s safe to drink. From how easy they are to use to plenty of affordable options that are easy on your budget, there’s a lot more to like.

Overall, an under sink filter might be the perfect solution to your dirty water problems. The benefits of having this type of filter at home include:

  • You can drink tap water safely.
  • There’s not a lot of equipment involved.
  • The systems are often affordable.
  • You can choose from a range of filtration levels and types.
  • You’re not filtering water that only winds up in the toilet or shower drain.
  • Most units don’t require electricity or batteries.
  • Installation is easier than with whole-house systems.
  • You can’t overfill your filter—water only flows when you need it.
  • Some units can run warm water and filter it, too.
  • They’re easy to use, since you just turn on the faucet.
  • No bulky equipment takes up space on the counter.
  • No one will see your water filter unit since it’s hidden under the counter.
  • You can use filtered water for cooking and washing dishes.
  • There’s very little water wasted—compared with reverse osmosis and other filter systems.
  • You can choose from different filter types and stages.
  • Filters usually last for at least six months before requiring changing.
  • Paying less per gallon for water than store-bought options.
  • No need to carry or transport water.
  • There are no plastic bottles to recycle.
  • Changing filters is easy and you can DIY.
  • You can choose to add minerals or remove specific contaminants with different filters.
  • You can keep your existing faucet if you choose.
  • An under sink water filter is easy to remove if you’re renting and need to move.
  • The system isn’t permanent—and you don’t have to cut pipes to install it.
  • You can customize the installation easily with tubing and connectors.
  • There’s no need to store water since it’s on-demand at the tap.
  • You can choose from different faucet types—or keep the one you have.
  • There’s no bulky attachment on the faucet—just a standard style spigot.
  • The filters are easy to change—usually, you unscrew the filter and re-thread a new one.

Under Sink vs. Countertop

Under sink water filtration systems are beneficial for many households. But countertop units offer similar features, too. If you can’t decide between an under sink versus countertop water filter, consider these facts.

  • Under sink water filters take up less space than countertop types.
  • Some countertop water filters don’t require installation—such as gravity-fed reservoir types. Every under sink type needs tubing to connect.
  • Under sink water filters don’t typically use electricity, while many countertop units do.
  • An under sink filter doesn’t require water storage: it’s on demand. Countertop filters may involve a reservoir for storing water.
  • Countertop filters might be easier to move, since some rest on the counter without connecting to your faucet. Under sink types must be uninstalled to move.
  • You can choose a countertop unit that stands alone, which makes it super-portable. All under sink options need tools to remove.
  • Some countertop units have tubing and faucet attachments that clutter your counter. Under sink styles hide everything from view.
  • A countertop system might not fit your décor. Under sink types are out of sight, and you can choose any faucet to pair with them.

Physical Advantages in Your Kitchen

Under sink water filters offer plenty of physical advantages. For one, they don’t take up any room on your countertop. Their space-saving design tucks underneath the sink cabinet, so you have a whole kitchen’s worth of counter space to work with.

Under sink systems are also low-profile, so you can still store things underneath your kitchen cabinet. Many types can be mounted on the wall of the cabinet, while others can sit upright. Either way, the narrow cartridges leave you plenty of space to store cleaning supplies or other kitchen items.

Having an under sink filter system is also beneficial because you don’t have to go anywhere to check on your filters or replacement status. Whole-house systems often install in the basement, where your pipes originate. That means you have to go down into the basement every time you need to check the filters or flush the equipment.

Of course, most under sink systems don’t require flushing anyway, which is a physical advantage since you won’t have to kneel under the sink often. Even if your system does require attention, you and your pipe cutters won’t have to visit the basement to handle it.


Types of Filters You Can Install

While under sink water filters are in their own category, there are a few different varieties included. There are also alternatives to true “under sink” options that you can still install underneath the kitchen sink.

In general, under sink filters come in a specific style. The filter cartridges usually resemble water bottles, in that they are tall and relatively thin cylinders. You can find systems with a single filter—though it might include multiple layers of filtration inside—and options with three or more cartridges.

But there are alternatives to these ‘standard’ under sink systems.

For example, under bench water filter systems can go underneath the kitchen cabinet. You may be able to install some countertop units underneath as well. It depends on the configuration of the system, of course, so you should always read the manufacturer’s installation guide first.

You might be able to install some countertop units under the sink if they don’t need power. Or, if you have an electrical outlet in the area, powered systems could still be an option. You may need extra tubing and connectors, but it’s often possible to modify a unit to fit where you want it.

Of course, you probably won’t be able to put a countertop, gravity-fed style water filter system under your kitchen sink. It would be too bulky, and you’d have to open the kitchen cabinet to get a drink of water.

Also, whole-house systems would be overkill for a single sink—and you wouldn’t get the benefits of filtered water anywhere else but in the kitchen.

Choosing the right type depends on what type of contaminants are in your water. But in general, there’s no such thing as “too much” filtration. The only problem is if your measurements are incorrect and the system won’t fit where you want to put it.


How Does It Work?

An under sink water filter connects to your main water line to filter water that flows to the tap. You get filtered water at the sink, but not anywhere else in the house. Unless, of course, you install separate units at every sink.

Many of these filters come with a new faucet attachment and tubing to connect everything. Others attach to your existing plumbing and hardware. There is installation required, but you don’t usually need to cut plumbing pipes or go purchase special equipment.

Between the faucet and your water supply are filtration units. You’ll find anywhere from one to five or more water filter cartridges on most equipment. Each stage cleans something different from the water. Some equipment re-mineralizes the purified water, too.

When you turn on the faucet, water flows from your home’s plumbing into the water filtration unit. It passes through each stage of filtration, leaving sediment and contaminants behind. Once the water reaches the tap, it has been cleaned and purified.  

Depending on the type of filter you choose, it may not need power to operate. Most under sink water filters use the power of your home’s water pressure to get water moving. That means no batteries to replace, no power connections to worry about, and never losing the ability to filter your drinking water.

One catch is that it can take a little extra time for water to come from the tap when you turn it on. This is because the water must pass through each filter on its way to the faucet. Of course, some units also have storage tanks, so you never have to wait for clean, fresh water.

With a storage tank, there’s always filtered water waiting under the sink. When you turn on the spigot, the water will flow almost immediately. Storage tanks take up more space than the standard under sink water filters, however, which is an important consideration.

Overall, under sink water filters don’t take up much space and offer multi-stage cleaning power for your drinking water. They’re simple to install and don’t take special equipment or a ton of time. They won’t clean the water throughout the rest of the house, but for drinking and cooking in the kitchen, an under sink filter does the job.


What Contaminants Does It Remove?

A water purifier for the sink can remove tons of contaminants. As to what contaminants a sink filter removes, the answer depends on the manufacturer. Many filter types handle chlorine, sediment, rust, and common chemicals in municipal water sources.

But you can also find filters that re-mineralize the water as it passes through the filter chambers. Some under sink water filters also remove lead, volatile organic compounds (VOCs), carcinogens, heavy metals, and even fluoride.

Many units promise to remove hard water minerals, so even your pots and pans will be healthier. Specific units reduce microbial cysts, herbicides, pesticides, pharmaceuticals, and more.

In short, the more filtration cartridges your system has, the more contaminants you can remove from the drinking water. Read the manufacturer’s descriptions carefully—including any provided test results—to see whether your top contaminant is on the list.

Also consider that some equipment is interchangeable—so you could add different filter types to your system depending on the water quality and your needs. For example, Filtrete filters come in three types: Advanced, Maximum, and Standard. Each level defends against a set range of contaminants, so you can choose a filter that fits your water’s quality and toxin load.


Pros and Cons

The pros of an under sink water filter are clear. With an under sink type system, you can drink clean water whenever you feel like it. You don’t have to fill a reservoir, press any buttons, or pour water from one container to another. Just turn on the tap, and water is available.

Of course, one drawback of on-demand water is it can take a little longer to fill your glass if you don’t have a storage tank. Kitchen sink water filters may slow your faucet a little bit, but most manufacturers promise a high PSI regardless.

Another pro is the ease of installation. Alternative systems require you to cut a piece of your plumbing to install the filters. That means lots of measuring, planning, and operating heavy equipment. Under sink systems might require some tubing modifications or connectors but adding them to your water line is easier.

Under sink systems are more portable than permanent water filters, but they’re also simpler to remove than whole-house systems. If you’re renting or living somewhere short-term, an under sink model is a good compromise between portable pitchers and permanent water purification solutions.

And finally, under sink options offer very little wastewater. In contrast, reverse osmosis and even distillation processes involve significant water loss.


How to Install

Installation should be straight forward with these units. Therefore, the steps outlined should work for most models.

  1. Remove current tubing from under the sink
  2. Clearly mark where you want the new filter to go
  3. Make all the plumbing connections first
  4. Add the filter and connect it to the sink
  5. Mount the filter in the marked location
  6. Test your new filter out

Note: The manufacturer will include information in the manual on how to install and how to test the water. Some units may require a bit of time running the water continuously before it is safe to use.


How to Replace or Change

The way you change or replace the filter will be subjective of the unit you own. However, here are some general guidelines.

  • Turn the water off
  • Open your faucet to allow water to drain out
  • Using the necessary tool, open the casing
  • Remove filter
  • Clean the inside of the casing
  • Replace filter
  • Close the casing
  • Check for leaks when you turn the water back on

Note: The manufacturer will provide you information on how to change the filter, you should adhere to this information. Additionally, all filters associated with the unit should be changed at the same time, no matter how they look.


Who Should Buy It?

Is a water filter for the sink a good option for you? It depends—on a few factors. The type of water you have will determine whether an under sink filter will help. Then, think about how much space you have for a water filtration system. If you don’t have much counter space, an under sink unit might be a no-brainer.

In general, an under sink water filter is excellent for people who need clean drinking water at their kitchen sink. It’s a smart solution for people with little counter space, and it’s also a good solution for people who are on a budget.


How to Correctly Do Maintenance for This Type

What’s great about under counter water filters is that they don’t usually require much maintenance. In fact, the only care your system will need is a thorough flushing when you first install it. Most systems don’t need regular flushing, which is one reason why they’re so efficient at cleaning water without wasting any.

So, the only maintenance you need to do on your system is replacing the filters. To make things easier, you should consider how to access the system before installing it. Make sure there’s room to maneuver any tools—such as a wrench—for removing the filters. You might even add extra tubing so you can remove the system from the cabinet to swap filters.

Changing filters is usually straightforward: twist the cartridge off the way you would untwist a bottle cap. Then, attach a new filter.


Common Problems and Fixes

There are always problems and issues that you are going to encounter with any device you have in your home. An under sink water filter is no different. Here are a couple of common problems and the fix.

A sudden drop in water flow rates

Solution: Often, when the water pressure changes, it is because of a filter issue. Either you have overused the filter, or the filter is clogged. When this happens, you want to replace the old filter cartridges with a new one. More often than not, you will find that the water pressure will stabilize.

Leaking in the under sink filter connections

Solution: Check that there are no cracks in the tubing. If the leak is coming from a fitting, using Teflon tape may help the issue. Moreover, if you have plastic fittings, replace them with brass fittings.


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