Saveourh2o is supported by its audience. When you purchase via our links, we may get a commission. Learn more

The Best Under Sink Water Filters for Great-Tasting & Clean Water

Writen by Ronald Brown

Fact checked by Natalie Bridges

Any family who wants only the safest and cleanest drinking or cooking water should get the best under sink water filter. Compact and discreet, a reliable under-sink water filtration system can remove unnecessary chemicals, particles, substances, and microorganisms from your water. It makes your kitchen adventures more enjoyable.

best under sink water filter

Of course, an under-sink water filter is not only great for the kitchen. You can install it wherever you have a faucet.

While all the products we recommend are of high quality, it’d help to learn some crucial factors you should not overlook while buying under-sink water filters. After all, these aspects will help you narrow down the most suitable choice for you and your family.

  • Type: Under-sink water filtration systems come in different forms, including reverse osmosis, ultrafiltration, and carbon block. Each type has pros and cons, with an RO system offering the most efficient and effective water contaminant removal.
  • Filter Capacity: A filter with a higher capacity means it’ll last for a longer time. Therefore, if durability is your top priority, you’d want to look for a better filtration capacity. While the product may be slightly more expensive, you don’t have to spend as much money to get a replacement as frequently.
  • Flow Rate: Homeowners need an under-sink water filtration system that does not reduce their plumbing fixtures’ average water flow rate. For instance, a kitchen faucet has a flow rate of 1.0 to 2.2 GPM (depending on the flow rate regulation where you live). Meanwhile, under-sink filters might have flow rates between 0.8 and 2.0 GPM.
  • Installation: Some under-sink water filtration systems are easier to install than others. For instance, RO systems might be more complicated to set up than conventional inline water filters, especially those requiring under-sink modifications.

The question now is how you can choose the top-quality water filtration system to install under your sink. How about we start with these twelve exciting products?

Top-Rated Products

Best Overall

iSpring RCC7AK


Most Budget-Friendly

Waterdrop WD-10UA


Best Value for Money



Table of Contents

Top-Tier Under-Sink Water Filter Reviews

1. iSpring RCC7AK Water Filter 

I can come up with only one statement about the iSpring RCC7AK. It is arguably the top-rated under-counter water filter system you can buy.

This product has six stages of water purification, tested to meet NSF standards to put your mind at ease. Most under-sink water filters only have a maximum of three filtration stages. This unit doubles that.

At the core of this reverse osmosis filter unit’s astonishing water contaminant-removal capabilities is a 0.0001-micron membrane. The smallest filtration membrane that other products use is 0.01 microns. Its superfine filtration makes this under-sink water purification unit the most suitable in removing almost anything in your water.

Dissolved solids will no longer bother you. So will sediments and microbes. This under-sink water filter serves as a home water purification system.

We know what happens if you run your water through a reverse osmosis membrane. You remove all the beneficial minerals from the water. That is not happening with this unit because it has a remineralization filtration technology. It returns beneficial minerals trapped by the RO system back into your water. You lose nothing.

I like this product’s completeness. It already includes all the hardware you need for installation. It even comes with an elegant, European-style faucet. I have to remind you that this product is quite bulky because of its six-stage design. For that, you might require a more professional installation.

The iSpring RCC7AK is the most exciting under-sink filter you can ever get for your family. It has the finest filtration membrane on the market, ensuring only pure water and healthy minerals will go into your glass or food.

What We Like
  • Six stage under-sink water filtration process for removal of contaminants
  • 0001-micron ultrafiltration RO system membrane for superb water purification
  • Recommended for reducing TDS, sediments, and microbes
  • Returns beneficial minerals to your water
  • Meets NSF standards for enhanced confidence
  • Complete set with installation hardware and a European-style kitchen faucet
What We Don’t Like
  • Some people may require professional installation

2. Waterdrop WD-10UA Water Filter

The most trusted under-counter water filters should never hurt your budget. Not only should these products be affordable to purchase, but they should also be cost-effective in the long run.

Waterdrop is listening. This brand offers one of the top-tier value under-sink filter systems on the market. The WD-10UA will not cost you a fortune. Since it also has an 8,000-gallon filter capacity that translates to a 1-year filter life span, it also turns out to be more economical than others.

Of course, great value does not only entail the price. It has to perform exceptionally well, too. This 3-stage under-sink water filter has ANSI/NSF certification that guarantees its 97% chlorine removal capability. It also has a kinetic degradation fluxion filter technology that eliminates as many heavy metals from your water as possible.

I absolutely love this product’s sleek and ultra-modern, all-black design. It is pretty surprising to know that this super-slim, 3.6-inch diameter unit has an 8,000-gallon filtration lifespan. Some bulkier products cannot even deliver half that. It also helps that the product has push-to-connect fittings for effortless installation.

Not everything is perfect about this under-sink water filter, however. Some people may find the accompanying installation manual inadequate. It seems the company assumes everyone has a basic knowledge of plumbing. The good news is that there are plenty of instructional videos to make DIY installation possible.

If any, it cannot remove total dissolved solids that might concern you. Let us get that clear.

The Waterdrop WD-10UA is one of the most exciting under-sink water filters you can ever install in your home. It has the backing of ANSI/NSF to give you confidence every time you get tap water from your faucet.

What We Like
  • Three stage under-sink water filtration system to remove heavy metals and more
  • Extra-long filter life span for less frequent filter change
  • NSF/ANSI certification for greater confidence about product quality
  • Sleek and ultra-modern design with push-to-connect fittings for DIY installation
  • Exceptional value for money
What We Don’t Like
  • Inadequate installation instructions
  • Not recommended for TDS reduction

3. FRIZZLIFE MK99 Water Filter

You only need to read one under-sink water filtration review to know that the FRIZZLIFE MK99 is an excellent product for your family. It will not break the bank, is easy to install, and does a phenomenal job of removing up to 99% of common contaminants from your cooking and drinking water.

This product has IAPMO R&T’s Seal for water quality. The organization tested and evaluated water samples from this system against ANSI/NSF standards. While the certification does not come from NSF, you will still feel safer about filtered water quality from your faucet.

This under-sink water filtering system removes chlorine, lead, mercury, sediments, VOCs, and more. You will also get clearer and fresher water to cook scrumptious meals and make refreshing beverages for everyone in your home. There is no need for a water filter pitcher because you can fill an ordinary pitcher with water straight from the faucet before you chill it in your fridge.

I like the inclusion of converter fittings to make it easy and fast to install. The filter cartridge’s design also allows for a three-second quick twist for effortless filter replacement.

Unfortunately, this system’s peak flow rate is modest at best. It can only run two gallons of water per minute. Some products have a 5 GPM rating. Its capacity is also lower than other brands at 1,600 gallons. This product may not be ideal for families with heavy water consumption.

Overall, the FRIZZLIFE MK99 still makes for a fascinating purchase. It has excellent water contaminant removal performance and is easy to install. It is perfect for small families or households with modest drinking water needs.

What We Like
  • Will not break the bank
  • 99% water contaminant removal performance for safe and better-tasting water
  • IAPMO R&T certification for confidence about system performance and quality
  • Kit includes converter fittings for easy installation
  • Quick-change filter cartridge technology for hassle-free filter replacement
What We Don’t Like
  • Shorter filter lifespan than other brands
  • Modest flow rate

4. Culligan EZ 3 EZ-Change Water Filtration

If you are looking for a simple under-counter water filtration system, you do not need to look further than the Culligan Advanced EZ 3. This product is compact and lightweight, so it should fit under your sink without any substantial modifications.

This under-sink water filter removes Class I particulates, chlorine, lindane, lead, and cysts. It can also address sediments in your water. It also improves water clarity and smell, making your drinks more pleasant and your meals more enticing.

The good news is that the filter head can accommodate several Culligan filter cartridges. You can replace the existing filter with one specific to the water contaminant you want to remove.

I like that this filter has IAPMO certification, although an actual NSF certification would have been better. Still, it reassures those who may be wary about its water contaminant-removal capabilities.

The EZ-Change technology is a real game-changer. Replacing the filter cartridge is as easy as twisting the housing and popping a new one up. It also has all the hardware you need to get it up and to run.

Its small filter cartridge can only mean one thing: a short life span. You must buy replacement filters every six months or after consuming about 500 gallons, whichever condition comes first.

However, it is one of the most efficient systems for removing Class I particulates to give your family members the quality and safe water they deserve.

What We Like
  • Recommended for Class I particulate reduction and more
  • Compatible with different Culligan filter cartridges
  • IAPMO certification against NSF standards for peace of mind
  • Unique EZ-Change system for effortless filter replacement
  • Easy to install with included hardware
What We Don’t Like
  • Shorter filter lifespan than other under-sink water filter systems

5. CuZn UC 200 Water Filter

If you need the most trusted under-sink filter for your home, I highly recommend the CuZn UC-200 Under Counter Water Filter. This product has the longest life span on this list. Its advanced three-stage filter also has bacteriostatic properties that other under-sink water filter systems do not have.

This product’s most important feature is its advanced coconut shell-activated carbon. The UC 200 makes your water more pleasant to drink from the faucet. It is clear, tastes awesome, and does not have any odd smell.

I like the addition of a KDF-55 filter in the UC 200. Not only does it remove heavy metals, inorganic compounds, and other contaminants, but it also inhibits bacterial and mold growth. Every glass of water you get from your filtered tap water is free of harmful molds and bacteria, leaving you more secure about your family’s health.

I believe this under-sink water filter system’s most significant advantage is its five-year lifespan. Most products I have seen have a one-year filter capacity, on average. Its extra-long life span should translate into better savings for your family.

Its Direct-Connect system also facilitates hassle-free installation, getting this unit ready in no time. That is additional savings for you.

While the UC 200 has a phenomenal water contaminant-removing performance, you cannot use it on well-water systems. The heavy sediments and heavy metals in well water can easily overwhelm the device’s micro sediment membranes. However, I think the UC 200 water quality results speak for its performance.

Its long life span, bacteriostatic capabilities, and ease of installation contribute to making the CuZn UC 200 the right choice for modern families.

What We Like
  • Three stage under sink water filtration mechanism
  • Advanced coconut shell activated carbon for odor and taste
  • Capable of inhibiting bacterial activity for safer water
  • KDF-55 for removing heavy metals, inorganic compounds, and more
  • Extra-long five-year filter life span for better savings
  • Direct-connect system for hassle-free installation
What We Don’t Like
  • Not for well water applications

6. Express Water RO5DX RO System

The Express Water RO5DX could be the top-tier under-sink water filtration system if only it had an alkalizing technology. It has almost the same water purification performance as the iSpring RCC7AK, the absence of the remineralization filter being the differentiating factor.

This water purification system has five filtration stages, while almost all products on the market only have three. It can remove up to 99.99% of chlorine, heavy metals, nitrates, VOCs, and more. This reverse osmosis system unit can also remove microorganisms, such as parasites and bacteria.

Good thing the company has NSF certification for its under-counter water filter. Otherwise, believing its water contaminant removal claims would be almost impossible.

I like the simplicity of its Quick Connect system. There is no way you will assemble the different components the wrong way. Everything is color-coded, allowing you to install this drinking water filter system. I also appreciate the addition of an emergency leak detector. If there is a leak in your system, this tiny device will turn off everything and save you water.

One advantage of this system is its expandability. You can always add a remineralization filter if you like. Adding a UV filter and a water softener to the whole system is also possible to further improve your home’s water purification.

I do wish this product provided more abundant water flow through its faucet. While 0.8 GPM is sufficient for the average family, some may find it wanting.

The Express Water RO5DX can easily beat other under-sink RO systems on the market. It is affordable, effortless to install, and has exceptional filtration capability to bring your family only the purest drinking and cooking water you can imagine.

What We Like
  • Advanced five stage filtration system with reverse osmosis technology
  • NSF certification to put your mind at ease
  • Color-coded Quick Connect system for easy installation
  • Emergency leak detector for more efficient operation
  • Customizable design for a more comprehensive home water purification system
  • Price is affordable
What We Don’t Like
  • No remineralization filter
  • Modest tap water flow rate

7. Filtrete 3US-MAX-S01 Water Filtration

If you perform an under-sink water filter comparison of entry-level systems, the Filtrete 3US-MAX-S01 will come out near the top. This product is not only right for budget-conscious families. It is also perfect for removing sediments, microbial cysts, lead, and other contaminants from tap water.

It is easy to claim 99% microbial cyst reduction, 99% lead removal, and 97% chlorine elimination. Any brand can put these figures in its marketing materials. However, Filtrete doesn’t just list these stats. Instead, they want to reassure you that these water contaminant removal figures have the validation and certification from the National Sanitation Foundation.

You should also know that this product has a higher water flow rate than other entry-level systems. Sure, 1.5 gallons per minute may not look like much. However, if you compare it to a system that can only provide 0.8 GPM, you know which is the better product. Filling your water pitcher for cooling in the refrigerator should be a breeze.

Installation is also never an issue. You can have this under-sink water filter serving your family in half an hour, saving up to $700 from getting a plumber to install it for you. That is another source of great savings for your household.

Of course, this product is not for you if you require TDS reduction. It is also worth noting that it only has a modest cartridge life span of half a year, translating to a more frequent filter change.

With its NSF-certified filtration performance, affordability, and ease of installation, the Filtrete 3US-MAX-S01 is a great find. Its operating cost may upset some people, but its performance is something everyone can appreciate.

What We Like
  • Efficient removal of lead, cysts, sediments, and chlorine
  • Higher water flow rate than other entry-level under-sink purification systems
  • NSF certification offers peace of mind for modern households
  • Recommended for budget-conscious families
  • Easy to install without professional help
What We Don’t Like
  • Modest cartridge lifespan
  • Not ideal for TDS reduction

8. Aquasana AQ 5300+.55 Water Filter

The Aquasana AQ 5300+.55 ticks all the boxes for a reliable kitchen sink water filter. Compared to other filters, the Aquasana AQ can remove more water contaminants to deliver fresh-tasting and clean water for everyone in a small household.

Its three-stage filtration technology removes as many contaminants as possible. You can rest easy knowing you only have about 1% of known contaminants in your drinking water. The Aquasana AQ is not perfect, but it is a lot better than other systems that can only remove about 90 to 95 percent of contaminants.

If you doubt this, the product’s NSF certification should put your mind at ease. You will sleep better knowing the glass of water you had before going to bed contains negligible amounts of lead, cysts, VOCs, heavy metals, and other impurities. The water you drink from the Aquasana AQ tastes better and smells nicer than ever before.

There is also no need to call a plumber. The company designed the Aquasana AQ under-sink water filter system for worry-free installation. It even comes with a modern faucet to replace your existing water fixture. Replacing the Aquasana AQ cartridge is also straightforward. You do not need to disassemble the whole unit.

My only concern about the Aquasana AQ is its lower flow rate compared to other brands I have seen. At 0.72 gallons per minute, it may not be sufficient for some households. The Aquasana AQ also has a capacity of only 800 gallons. I have seen under-sink water filter systems with a 10,000-gallon capacity.

The Aquasana AQ 5300+.55 may pale compared to other products regarding capacity and water flow rate. However, nobody can question its water contaminant removal performance, ease of installation, and reliability.

What We Like
  • Ideal for small households
  • Three stage filtration system for efficient contaminant removal
  • NSF certification for guaranteed filtration performance
  • No plumber necessary for installation
  • Cartridge replacement does not require complete system removal
  • One faucet included
What We Don’t Like
  • Lower flow rate than other systems
  • Smaller filter capacity than other under-sink water filters

9. 3M Aqua Pure 70020007418 Water Filter

If you are like some of us, you do not need a complex under-sink water filter system. If your only concern is the bits of sediments and the uncanny chlorine odor and taste in your water, this 3M under-sink water filter should do the trick.

The Aqua Pure is a neat-looking and compact device that you can easily install under your sink. It has a smaller space requirement than other brands, allowing you to maximize whatever space you have left under the sink.

Note that this product only removes sediments and chlorine, including the odd taste and odor. Like many 3M products, this under-sink water filter has an NSF 42 certification. You can go to bed feeling secure that your family members had the best-tasting water or prepared beverage at dinner.

While you might not like its six-month cartridge life span, you have to credit the company regarding the filter’s design. This device is small, which makes it surprising to know that it can last that long. Similarly-sized products can only last about three to four months.

I like this water filter’s design simplicity. Its all-white styling should keep your under-sink space looking bright and tidy.

Given that this product only removes chlorine, odor, taste, and sediments, I find its price tag to be a bit unjustified. Some products cost half the price yet are capable of removing more contaminants.

Additionally, the under-sink water filter’s construction is a little fragile. Some customers complain of breaking the unit during filter replacement. Most people advise caution when twisting the cap as it can easily break.

The 3M Aqua Pure is the right choice for families that only want better-tasting water straight from the faucet. Its NSF certification puts your mind at ease.

What We Like
  • NSF 42 certification
  • Provides great-tasting and clean drinking water
  • Excellent filter life span given its size
  • Clean and simple filter cartridge design
  • Small and compact design for better space-savings
What We Don’t Like
  • Quite expensive for its list of removable contaminants
  • Careful handling required to avoid breaking the unit

10. AQUACREST 5KDC Water Filtration

In general, the more filtration technologies included in an under-sink water filter system, the more expensive it is. That is why sediment filters are always the cheapest. Would it surprise you if I said that the AQUACREST 5KDC is more affordable than a sediment filter?

Unbelievable but true. This under-sink water filter system uses two popular filtration mechanisms: a 0.5-micron coconut shell activated carbon filter and a kinetic degradation fluxion filtration membrane. These filter media are at the core of this under-sink water filter for half the price of the leading sediment filter-only system.

You may say that its low price translates to mediocre filtration performance. It does not. This unit has NSF 42 and NSF 372 certifications, putting your mind at ease. Not only does it cleanse your water of chlorine and its unpleasant taste and odor, it also removes fluoride, lead, aluminum, arsenic, VOCs, and other heavy metals.

You might also think that this product has a short cartridge life span. That is not the case. This under-sink water filter can accommodate 5,000 gallons of water before requiring any replacement. It is hassle-free to install, too.

The water flow rate is also not a problem. At 1.5 GPM, it is a lot better than the 0.72 GPM of one of the leading brands.

However, it would be pointless to use this product if you have well water. Its design is for municipal and city water sources only. It will also not lower your TDS levels, regardless of how efficiently it removes heavy metals and other contaminants.

The AQUACREST 5KDC is perfect for budget-conscious families that deserve only the top-rated for their home. Its faucet filtration performance is commendable, and its overall design lends it exceptional value for your money.

What We Like
  • NSF 42 and 372 certifications for guaranteed filtration performance
  • Higher water flow rate than other brands
  • Higher capacity filter than similar brands
  • Inexpensive KDF and activated carbon filter combination
  • Easy to install
What We Don’t Like
  • Not recommended for well water sources
  • No effect on TDS

11. Hansing Full Flow Water Filter

Some people think that Chinese brands have mediocre quality. Hansing proves them wrong. The company’s tankless Full Flow Under Sink Water is an affordable system for modern home. It can also outclass some of its Western counterparts.

Inside this under-counter water filter is a three-stage filtration unit that features a sediment filter, a coconut shell activated carbon, and a KDF-55 filter. These elements are the same media you get from reputable US water filter manufacturers. The company also designed its products specifically for American homes.

Its radial flow carbon block design is excellent. You will never experience a sudden drop in your water pressure since it handles up to 30% higher water pressure than what we see in the market.

This system also has a higher filter capacity than many leading US brands. At 13,000 gallons, you can expect to replace this unit’s filter after about three to four years. On top of that, its water flow rate is also commendable. It can provide you with 2.6 gallons of water per minute, almost four times other systems’ water flow rate.

I also like its filter housing because it looks tough. It should if its filter cartridge can last that long.

The downside here is that this product does not have NSF certification. There is no way of guaranteeing its lead, chlorine, chloramine, mercury, chromium, and cadmium removal capabilities. You will only know it is effective when you drink your water from it.

This Hansing under-sink water filter system may not have the prestige of its American counterparts. However, it can outclass and outperform some of the so-called most suitable of the West at a price that will never hurt your bank.

What We Like
  • Three-stage system for effective removal of contaminants
  • Solid carbon block with radial flow technology for consistent water pressure
  • Higher filter capacity than similar under-sink water filter systems
  • Higher water flow rate than other products
  • Heavy-duty filter housing construction for improved durability
  • Budget-friendly product
What We Don’t Like
  • No NSF certification
  • Some customers may have an issue with a Chinese brand

12. Woder WD-10K-DC Water Filtration

Most of us think that a drinking water filter system’s filtration capacity is a function of its filter size. The smaller the filter, the lesser is its filtration capacity. It will blow your mind to learn that the Woder WD-10K-DC defies any preconceived associations between filter size and filter capacity.

With only a 2.5-inch diameter filter unit removing water contaminants, it is remarkable that this product has a filter capacity of 10,000 gallons. Most under-sink water purification systems on the market can only muster about 500 to 1,000 gallons. They also have a bulkier filter cartridge than this Woder product.

You have to give credit to the company for its ingenious filter design. It would seem impossible to have that impressive capacity in such a small and compact unit. Yet, this water filtration for the kitchen sink has the WQA Gold Seal certification to back up its claims.

You can say goodbye to about 99.9% of lead, chlorine, heavy metals, VOCs, and other water contaminants. Start saying hello to fresh, clean, pure, and great-tasting water for your home.

Its Direct-Connect system also makes it effortless to install under your sink. As long as you have a 3/8-inch pipe, you should be okay.

While I admire its water contaminant-removing capability, it does not soften water. It will also not reduce total dissolved solids. If these are what you want from an under-sink water filter, you might want an RO system or a water softener instead.

The Woder WD-10K-DC is one of the most astonishing water purification systems you can install under your sink. It is compact and lightweight but can outlast other bulkier under-sink water filter systems on the market.

What We Like
  • High-capacity system for better savings
  • WQA Gold Seal certification for water filtration performance assurance
  • Ultra-slim profile for exceptional space-saving
  • Direct-Connect system for worry-free installation
What We Don’t Like
  • Not for softening water
  • Incapable of lowering TDS

What Is The Top-Tier Under Sink Water Filter/ Who Is This For


The right under-counter water filter provides you with the safest water you can ever drink, cook your favorite dishes and make exciting drinks with. It removes as many drinking water contaminants as possible, including chlorine, chloramine, mercury, lead, arsenic, and other heavy metals.

Total dissolved solids will never be a concern depending on the water purification system you choose. There is also no worrying about bacteria, parasites, cysts, fungi, and other biological contaminants. If you choose wisely, you can also inactivate certain viruses.

Some companies also provide under-the-counter water filtration systems with built-in water conditioners. Please do not confuse these elements with a water softener. However, they can prevent limescale formation and preserve your water appliances’ integrity and overall function.

The National Sanitation Foundation classifies an under-sink water filter as a point-of-use system. You install it near the faucet where you intend to obtain filtered drinking water. In general, you can find this system between your kitchen cold-water line and the kitchen faucet.

An under-counter water filter is a right choice for families requiring safe and clean cooking and drinking water. They do not mind having unfiltered water for cleaning, watering plants, washing clothes and dishes, and bathing.

It is also better than a water filter pitcher because there is no substantial waiting period before you can drink water. You can drink straight from the faucet.

An under-counter water filter is also better than a faucet filter. While the latter is less expensive than an under-counter system, it does not provide sufficient water flow. With the right under-sink water filter, you will never worry about reducing the water flow in your kitchen sink.

How Do Under Sink Water Filters Work

An under-counter water filter works in different ways, depending on what contaminants it needs to remove or neutralize. In general, these systems’ principal function is to separate water molecules from other substances.

Some systems push water through a semipermeable membrane. Contaminants with a diameter larger than a water molecule cannot pass through this layer. Most of these products feature a granular activated carbon filter technology, while others also employ kinetic degradation fluxion to trap heavy metals.

Carbon filter also has absorptive properties, allowing it to remove unnecessary tastes and odors that can make drinking water less desirable.

A high-end carbon filter media can remove bacteria, parasites, cysts and other biological contaminants from your drinking water. However, it cannot remove or kill smaller microbes such as viruses. Only products with UV filtration devices can neutralize these microorganisms by exposing them to ultraviolet radiation.

Other systems push more water across a concentration gradient by increasing osmotic pressure on one side of the filter gradient. Contaminants that do not resemble water get left behind.

Some under-sink water filters release chelating agents into the water to attract magnesium, calcium, and other hardness minerals. These products work like water softeners without removing magnesium and calcium ions.

What Are The Different Types Of Under Sink Water Filters

best under sink water filter

Water filtration systems are essential components of a safe home. They afford homeowners and their families safer and cleaner water to drink. Buying the right system for your family requires knowledge of your options. Water filters for under-sink applications come in at least three types. They are as follows.

  • Sediment Filters

These filters remove large particles and other contaminants at least 5 microns in size. They can include dirt, sand, silt, rust, debris, and other particles present in water. These filters do not address aesthetic water qualities, such as unpleasant tastes and bad odors. The filtration process is similar to a sieve that makes excellent pre-filters.

  • Carbon Filters

Carbon filters often use activated carbon, although some products use other carbon filtration technologies. These filters usually have a filter size ranging from 0.05 to 0.5 microns. Their pore size allows these filters to remove bacteria, cysts, parasites, and biological contaminants with a diameter larger than the filter’s pore size.

Carbon block filters are also ideal for addressing tap water’s unpleasant taste and odor, often attributed to chlorine and chloramine. They can improve the taste characteristics of your drinking water.

Some carbon filters have a kinetic degradation fluxion technology. This system removes heavy metals, such as lead, iron, aluminum, arsenic, mercury, and more.

  • Reverse Osmosis Systems

A reverse osmosis system is perfect for households that have issues with their total dissolved solids. RO systems push more water molecules across a membrane, trapping other molecules and contaminants on the other side of the semi-permeable membrane.

An RO system is quite different from the usual filtration process. Whereas ordinary filters move water passively, reverse osmosis actively moves water across the membrane. RO systems provide a unique way of removing contaminants.

The problem with a reverse osmosis system is that it also removes beneficial minerals. That is why many RO systems include a remineralization chamber that reintroduces removed minerals into the water.

  • Ultraviolet Systems

Although rare, you might encounter an under-sink faucet purification system that uses ultraviolet radiation. These systems are ideal for inactivating viruses in the water by interfering with viral replication. Ultraviolet radiation can also inactivate other susceptible microorganisms from your faucet water.

These products are ideal for anyone who wants germ-free drinking water straight from their faucet. Take note that such filtration technologies are more expensive than conventional carbon block filters.

Advantages And Disadvantages Of Using An Under-Sink Water Filter

Installing a water filter under your sink can offer you a few advantages.

  • Retains your kitchen aesthetics

Under-sink water filters will never detract from your kitchen décor. Compare this with a countertop model. No one will ever know you have a water filter under your sink. Some products also come with a matching faucet to improve your kitchen aesthetics.

  • Efficient removal of contaminants

Depending on the water filter type you choose to install under your kitchen faucet, you can remove as many contaminants as you need. For example, sediment filters will be an excellent choice if you only need to remove large particles.

If you need the removal of microbial contaminants, a UV filter will work best. However, carbon filters and RO systems are also sufficient in many cases. Heavy metals, VOCs, pharmaceutical agents, and other contaminants will no longer bother you.

  • Longer cartridge life span than other systems

The cartridge life span of an under-sink unit is longer than that of a water filter pitcher or a faucet filter. The filtration unit has a larger surface area, allowing it to accommodate more water. On average, under-sink purification systems can last up to twelve months. Most faucet filters can only last about two or three months.

  • More economical than some water filters

You can get a water filter for your sink for less than $50. High-end units can set you back for about $200. The replacement filters are also cheaper than those found in whole-house systems. The long lifespan also makes these water filters more economical than faucets or water pitcher filters.

Here are the disadvantages of an under-the-sink water filter you need to know.

  • Filtration for a single faucet only

It is essential to understand that under-sink filters only filter water going to one faucet. If you install it in your kitchen, only your kitchen faucet will have filtered water. You will have to install additional units to other faucets in your home if you want clean water elsewhere. In that case, whole-house water filters might be a better option.

  • Space requirements

Under-sink filters are more miniature than whole house filters. However, some filters may not fit under the sink. You may have different pipes running under your sink. You may want faucet filters instead.

Buying Guide


Whether you live in the US, Australia, Singapore, the UK, Japan, or any other country worldwide does not matter. Everyone deserves clean, safe, and great-tasting water to drink or to use in making meals and beverages straight from the faucet. While you can pick a faucet water filter or even a whole house water filter system, an under-sink water filter makes more sense sometimes.

The question is how you can choose the best under sink water filter to install in your home. Here are some things you need to consider when picking and buying a water filter under your sink.

Flow Rate

It is always ideal for getting an under-sink filter with at least the same water flow rate as your kitchen tap water flow rate.

For example, the average kitchen tap water flow rate is about 1.5 GPM. If you pick a water filter with a lower flow rate than 1.5 GPM, you may not be able to enjoy using your faucet. Filling a glass with water takes a longer time, and this can be a problem if you are in a hurry.

Keep in mind that elevation and water pressure play a role in water flow. If you live on the upper floor of a high-rise residential building, your water flow rate may be lower than those on the lower floors. It is especially a concern during peak hours when everyone uses water almost simultaneously.

Filter Capacity

Most of us want an under-sink filter system that can accommodate as much water as possible before requiring replacement. Think about it. The smaller the filter capacity, the faster it can get clogged, and the more frequently you will have to replace it.

Some under-sink water filters have a 500 to 1,000-gallon filter, filtering only this much water. Some products offer a higher capacity, ranging from 5,000 to 15,000 gallons. Of course, there are also products in between, such as the PUR under-sink water filter with a 3000-gallon capacity.

In general, units with a higher filter capacity tend to be more expensive than those with a lower filter capacity. Other factors can also play into the product’s final price.

Micron Rating or Filter Pore Size

Under-sink water filters have filtration membranes that range in pore size from 0.0001 microns to 10 microns. Here is what you need to know. The smaller the micron rating, the more particles it can trap or remove. Unfortunately, it also clogs much faster than a filter with a higher micron rating.

Sediment filters often have a pore size of 5 to 10 microns and are ideal for removing larger particles, such as those in well-water systems. Carbon filters have pore sizes between 0.1 to 0.5 microns, allowing them to remove almost any other water contaminant. Some systems offer a 0.0001-micron rating. These products can filter viruses and other microscopic organisms.

Because water can have a mixture of different-sized particles, it is often best to buy an under-the-sink water filter with at least two filtration technologies. You must have a sediment pre-filter component to remove large particles and prevent clogging the carbon filter unit’s pores.

Ease of Installation

Most under-sink water filters are straightforward to install, requiring only the filter unit’s on a surface under your sink. Some units can stand on their own, known as under-sink water filters, no drill systems.

Reverse osmosis systems have an additional tank that can pose some issues during installation. It is not a problem if you have sufficient space under the sink.

Ease of Filter Replacement

Filter replacements should also be straightforward. Thankfully, many companies design their products with an easy-twist mechanism. A simple flick of a lever and a twist of the filter housing are all it takes to remove the filter cartridge. You do not need a wrench, although some brands provide filter housing wrenches.

The ease of filter change has as much to do with the filter’s design as its construction. You do not want a filter head or canister that breaks easily with every attempt at disassembly. You will want to retain your filter unit’s integrity every time you replace the filter.

You should also check the availability of compatible replacement filters. You should know that some replacement filters are only specific to a brand of under-sink drinking filter.

Cartridge Life Span

Your unit’s cartridge life span is a direct function of its filter capacity. As we already explained, the higher the filter capacity, the more water the unit can accommodate. You can prolong your cartridge’s life span if you do not use that much water.

Say your household only consumes about three gallons of water from your kitchen faucet daily. You will be consuming about 1,100 gallons per year. If you get an under-sink filtering system with a filtration capacity of 800 gallons, you can expect the cartridge life span to last only about eight to nine months.

Suppose you consume five gallons per day. You will need a unit with at least a 1,800-gallon capacity to last a year. Using the same 800-gallon unit will only last you about five months.

Customer Support

Many Reddit contributors and members underscore the importance of exceptional customer support. It can come in an easy-to-read instruction manual or an easy-to-follow instructional video.

Unfortunately, even a well-written owner’s manual can still be problematic to some people. They may need someone to describe the step-by-step process of installing, maintaining, and troubleshooting their under-sink water filter.

You can always reach out to potential sellers before you make any purchases. Try to evaluate how they respond to your queries. Is the representative enthusiastic about providing you with the answers you need? It would be nice to evaluate the interaction and determine if the company is worth doing business with.

Another method is to look at reviews. While biased, customer reviews can provide you insight into customer experiences related to customer support. You may notice varied responses. Pick recurring themes because these can be red flags for you.


While not necessary, it would help if the under-sink filtration system you want for your home has the correct certification from a reputable organization. Ideally, a certification from the National Sanitation Foundation (NSF) International guarantees whatever claims the company has on its product.

However, not all companies have an NSF certification. They may employ other third-party organizations to test and evaluate their products against ANSI/NSF standards. Examples of these organizations include the Water Quality Association (WQA) and the International Association of Plumbing and Mechanical Officials (IAPMO).

Initial and Running Costs

Price is always a major consideration. In general, the fewer filtration system technologies involved, the less expensive the filter system. So, if you purchase a product with reverse osmosis, carbon block filter, sediment pre-filters, and KDF filters combined, expect the price to be higher than a product with only one of these filtration technologies.

The cost of maintaining your unit also matters. As explained above, systems with longer life spans require less frequent filter replacements. You only need to purchase replacement filters once a year or once every five to ten years.


Product warranty is a sensitive issue among modern consumers. It reflects product quality because the company is willing to replace or repair its product if it performs below expectations or has inherent flaws.

Generally, a 60-day money-back guarantee is better than no warranty. Some companies offer a 1-year warranty on their parts, while others provide a more extended 5-year warranty. If you get a product with a lifetime warranty, that will be an exceptional find.

Frequently Asked Questions (FAQs)

Are under-the-sink water filters worth it?

Yes, an under-sink water filter for well water is worth it, especially if you are on a tight budget and cannot afford an advanced, multi-stage whole-house water filtration system.

It is also a worthy investment if you want a reliable system for getting safe drinking water straight from the tap without resorting to bottled water again.

A water purifier under the sink offers a semi-permanent solution to safe on-demand water than other point-of-use water filters, including a water filter pitcher, faucet water filter, and a countertop water filter.

How long does an under-sink water filter last?

An under-sink water filter has varying lifespans, depending on its filtration or water purification technology. It is worth noting that an under-the-sink drinking water filtration system can feature multiple stages of filtration.

For example, RO semipermeable membranes have an of about two years, while carbon pre-filters and sediment filtration cartridges can last six to nine months. Meanwhile, carbon post-filters can continue working for up to a year.

How often should you change the under-sink water filter?

An under-sink water filter replacement frequency depends on the component’s average lifespan. For example, a sediment or carbon pre-filter might only last six months, requiring a twice-yearly filter change.

Meanwhile, carbon post-filters have a 12-month lifespan, requiring an annual filter change. Under-sink water filtration systems for renters with RO technology can last two years. Hence, you will only replace the semipermeable membrane five times a decade.

The easiest way to know when to change the filter is to divide its capacity by the total volume of water you use per day. For instance, assume that you use the previously reviewed PUR PFM400H (which has a filter capacity of 320 gallons) and consume 2 gallons of water from the sink daily, then get a replacement after 160 days.

How can I make my filters last longer?

Here are some tips to make your water filters for home applications last longer.

  • Clean the water filter as regularly as possible to prevent unnecessary buildup of water impurities. Most under-sink and inline water filter manufacturers have maintenance recommendations, including how to clean the filters and what agents to use in cleaning.
  • Research the various components of your under-sink water filter. Each element has a different mechanism of action, requiring a different maintenance and care approach. Take time to read the user manual because it can help improve filter lifespan.
  • Avoid using the under-sink water filter immediately after heavy rainfall because the well water will be full of sediments and other contaminants. These particles can shorten the water filter’s lifespan. Store water before the storm hits to make your filters last longer.
  • Be mindful of your water consumption. Increased wastewater not only translates to higher water bills. It can also shorten your water filter’s lifespan because these products have a limited capacity.

What brands make top-quality under-sink water filters?

Many homeowners trust a GE under-sink water filter because of its effortless installation, impressive water quality improvement, and extensive water filter cartridge compatibility.

Although more popular for its existing faucet water filters, Brita remains a trustworthy brand when it comes to water filter for sink systems. Its Total 360 BRDROS Undersink RO System is an excellent example, offering ultra-fast flow rates and efficient water contaminant removal.

Hydroviv is another water filter brand worth considering. Featured on Shark Tank, this compact water filtration system uses RO technology to improve water quality by eliminating heavy metals, harmful chemicals, and other toxins.

Aquasana, A.O. Smith, APEC Water Systems, and Waterdrop are a few other under-sink water filter brands worth considering.

Under-the-sink water filtration systems need regular maintenance. The sediment and carbon filters last for 6-9 months on average, and the post-filter has a filter life of 12 months. In reverse osmosis systems, the semi-permeable membrane lasts on average for about 2 years.

What are the most trusted under-sink water filter brands?

Culligan, 3M, Woder, and Aquasana continue to blaze the under-sink filter system trail. You will never go wrong with these brands’ products. Most of their water filters have third-party quality testing and certification if not the National Sanitation Foundation’s actual certification. Their products are reliable, durable, and perform exceptionally in real-world situations.

Express Water and iSpring are not far behind. These two brands also make exciting water filters that many consumers are now using in their homes. You can rest assured their product offerings are just what your home needs.

Other trustworthy under-sink water filter brands include WaterDrop, FRIZZLIFE, CuZn, Filtrete, Hansing, and AquaCrest.

You might also want to read the different consumer reports for these under-sink water filters. It should give you insight into each brand’s strengths and weaknesses, helping you make a wiser buying decision.

What size under-sink water filter do I need?

The size of the under-sink water filter you need for your home depends on a few things. First, you have to check the space under your kitchen sink. Most under-sink water filters can fit in under-the-sink cabinet spaces. However, reverse osmosis systems often have an extra tank that can take up additional space. Some products are also bulkier, usually involving more than two filtration tanks.

Another consideration is the filter’s maximum rated capacity. It would be most suitable to pick a product with the same water capacity rating as your average daily water consumption. Say you use about five gallons of water from your kitchen faucet every minute. It makes sense to get a system that offers that much water, too.

How to remove under sink water filter?

There are instances when you no longer want to use an under-sink water filter, such as when a whole house water filter makes more sense. Here is how you can remove your under-sink water filter.

  1. Turn off the cold-water shutoff valve and open your faucet to let all the water out.
  2. Look for the flexible tubing that connects the cold-water pipe to the water filter unit. Disconnect the tubing at the cold-water pipe end.
  3. Disconnect the hose connecting the filter unit to your faucet pipe.
  4. Remove the under-sink water filter system.
  5. Connect and secure a hose from the cold-water pipe to the faucet pipe.
  6. Turn on the cold water shutoff valve and open your kitchen faucet.
  7. Check for any signs of leaks.

There is no need to remove the entire under-sink water filter system if you only need to perform a filter change. Most products come with a housing wrench to unscrew the filter housing. Remove the housing and replace the filter cartridge with a new one. Replace and secure the filter housing to the filter unit head.

How to install under sink water filter system?

You can install a water filter under the sink in simple steps and with a few basic plumbing tools. There may be minor modifications to this procedure, depending on the under-sink water filter type you will install. Nevertheless, the steps are essentially the same.

  1. Turn off the cold-water shutoff valve, open your kitchen faucet, and use a wrench to disconnect the waterline.
  2. Position the under-sink filter unit where it will connect to the waterline. Mark the location for the mounting holes and drive a few screws about halfway through.
  3. Remove the under-sink water filter head and connect the flexible tubing and pipe fittings. Most products already have this pre-assembled for effortless installation.
  4. Return the under-sink filter unit head under the kitchen sink and secure the mounting screws. Install the filter housing with the cartridge inside.
  5. Connect and secure the cold water line to the water filter inlet port.
  6. Connect and secure the filter unit to your faucet stem.
  7. Turn on the cold-water shutoff valve and open your faucet for about five to ten minutes to prime your under sink water filter system.

How to care and clean?

Cleaning and caring for an under-sink water filter requires knowledge of your unit’s unique design and characteristics. Manufacturers have specific guidelines and recommendations on how to best care for their products. It would be wise to read the owner’s manual before you attempt to clean and maintain your faucet water filtering system.

Carbon filters require periodic cleaning that involves rinsing the filter with clean water and soaking it in a special cleaning solution. Do understand that most carbon filters are not washable. It would be most suitable to check your manual to see if you can wash your carbon filter media.

Reverse osmosis membranes are pretty delicate. You can remove the RO media and use an appropriate cleaner to sanitize it. A professional cleaner can help you maintain your RO system’s integrity if this is too much of a hassle.

Systems that integrate UV filtration may also require special treatment. Always refer to your owner’s manual or seek professional cleaning.

In general, you should always keep the under-sink water filter housing clean and clear of dust and debris. It is also most useful to check the connections, ensuring there are no leaks or signs of damage.

Where to buy?

Today, most shoppers always log in to the Amazon marketplace because of its wide selection of under-sink filter systems. The e-commerce giant also provides exceptional customer support, addressing your queries if you have one.

Most consumers love reading an under-sink water filtration system review because of the real-world experiences people share about these products. It makes choosing a lot easier.

You can also check out retailers on eBay, although you may not be able to get the kind of support you need. It remains an excellent marketplace to source your water filtering system, nevertheless.

Lowe’s, Home Depot, and Sears are always dependable e-commerce platforms to buy your next under-sink water filter. However, the selection may not be as extensive as what you get from Amazon. It remains a good option for those who want the best.

Manufacturers’ official websites are also excellent places to buy under-sink water filters.


The best under sink water filter is better than a countertop filter or a water filter pitcher. It provides your family with safe, clean, and great-tasting water to drink and use for cooking and washing food items in your sink. It removes common contaminants that can affect water quality and you and your family’s health.

5/5 - (4 votes)