Best Under Sink Water Filters (Review) in 2020

  • Effective in removing contaminants and other heavy metals​
  • NSF listed
  • Faucet included
  • Effective in removing iron, chlorine, lead and other heavy metals
  • UV light to destroy microorganisms
  • Faucet included
  • Reduces chlorine, sediments, lead, heavy metals,
  • Easy installation
  • Filter lasts 5 years

Anyone who goes through more than a couple of gallons of drinking water a day will probably be happiest with an under-sink filtration system like the Home Master TMHP HydroPerfection. If you prefer (or need) filtered water, this provides a continuous supply of it on demand from a separate tap. We recommend the Home Master TMHP HydroPerfection because its certifications are among the best of any system we’ve found.

Out of more than 10 brands of undersink water filters we found on the market, we picked out the best four reverse osmosis filters and one simple filter following the criteria of filter quality and lifespan, water efficiency, and price.

View the The Best Under Sink Water Filters of 2020 on the Market, Below.


Home Master TMAFC-ERP Under Sink Water Filter

The Home Master TMAFC-ERP Artesian is an under-sink water filter that sets the standards for others in the industry with its efficient and long-lasting filters, and a pure water:waste water ratio of 1:1.

A Complete, Well-rounded System

The TMAFC-ERP Artesian is made in the US with NSF certified components by Perfect Water Technologies, Inc., an NSF listed manufacturer.

This package of under-sink water filter comes with an RO membrane, pre-filters to protect said membrane, a post-filter and remineralizer for alkalinization of the water after filtration, a tank for pure water storage. Also in the package are a drain saddle, fittings, tubing, and an adapter. It also includes a faucet so that you can have purified water from a separate tap.

That’s everything you need for pure alkaline water from your own kitchen.

Improved Flow Rate And Incredibly Low Waste

One of the biggest problems with RO water filters is that they tend to produce lots of wastage before they can offer a gallon of clean water. The waste:purified water ratio can sometimes get as high as 5:1.

The Home Master TMAFC-ERP comes with a permeate pump that works to improve the system efficiency. It reduces up to 80% of wastewater. As a result, the waste:purified water ratio is probably the lowest among reverse osmosis systems: 1:1.

The good thing is, this pump uses energy from the reject water, and thus doesn’t even require electricity to work!

Super Effective Water Filtration

The system includes a set of 3 filters:  a spun poly sediment filter, a catalytic carbon filter, a coconut shell granular activated carbon water filter, and the RO membrane. When water comes out of your faucet, up to 99% of dissolved solids, chemicals & metals are already removed.

The catalytic carbon filtration media in the pre-filter is a special feature in this system. This material is one of the few that are highly effective in removing chloramine, a chemical disinfectant used widely in the US to replace chlorine.

Not only that, but the Artesian remineralization also allows healthy minerals, calcium and magnesium in particular, back into the water, making it slightly more alkaline. This will show in your water TDS reading, so don’t be surprised if the number’s above zero!

Innovative Filter Design

In traditional RO systems, the filter housing is kept for re-usage every time a filter is changed, posing risks of re-contamination. The Home Master TMAFC-ERP, meanwhile, has a modular filter design, where the filter and its housing are incorporated into one single unit and are disposable together. This makes it slightly more expensive, but is better hygienically.

These filters can last about 2000 gallons, and it is recommended by the manufacturer to change it once every year. (Replacement filter)


This is probably the easiest RO system to install on the market. The membrane and filters come readily assembled, so you don’t have to worry about it.

Installation typically takes about 50 minutes.

The process may involve some drilling and screwing, however, for the filtered water dispenser. Therefore, if you’re not exactly a handyman or handywoman, it’s best to ask for the help of a plumber.


  • Effective in removing contaminants
  • Low waste water ratio
  • Fast flow with pump
  • Alkaline water
  • Faucet included
  • NSF listed


  • The loaded package is a bit pricey to most people (but it’s worth every penny!)


  • Brand: Home Master
  • Model: TMAFC-ERP
  • Weight: 14.5 pounds


Home Master TMHP Reverse Osmosis Filter System

Most RO filtration systems can work very well on tap water. Well water, however, is a different story.

Unlike tap water, well water is usually not treated with chlorinechloramine, or fluoride. Therefore, such chemicals are much less of a problem. Sediments such as sand, rust, and microorganisms and heavy metals, however, are very often found in well water.

In many parts of America, well water is usually specifically rich in iron. While it’s unlikely that you can get an overdose of the metal from drinking the water, iron usually comes with trace impurities and harbor bacteria which are potentially harmful. It also tend to leave rust stains on your sink and ceramic dishes.

So, if you’re using water from a private well, you want a filtration system that can take care of the iron, the microorganisms, along with other heavy metals, at the same time softening the water.

There’s one that is designed to take care of the job: the Home Master TMHP HydroPerfection.

An Advanced Purification And Softening Process

With an RO membrane, the HydroPerfection is among the most effective under-sink water filtration systems to purify and soften well water.

To prevent iron from damaging the RO membrane, the system is also equipped with an iron pre-filter which contains advanced redox media KDF85.  Together, the RO membrane and the pre-filters can clear out 99% of chemicals, heavy metals (water-soluble lead, mercury, nickel, chromium, ect), sediment, pesticides, and other contaminants. It also removes 98% of iron, eliminating the typical metallic taste from well water.

Uv Light To Get Rid Of Viruses And Bacteria

After passing through the RO membrane, the water is essentially purified. To further make sure it’s free of any disease-causing microorganisms, a UV light, one of the 4 methods approved by the FDA to purify water, is employed.

This light that produces short wavelengths is known for being effective at breaking molecular bonds within the organisms’ DNA and killing or disabling them. So, any bacteria and viruses that can pass through the RO membrane will be destroyed in this process.

But the HydroPerfection doesn’t stop there…

Alkaline Water

After purification, the water is often time slightly acidic. This is because the RO membrane is so effective it happens to also filter out essential minerals from the water.

The Home Master HydroPerfection offers remineralization at two points. It releases a small amount of minerals before the water travels into the tank (to prevent tank degradation from the acidic water)  and before it gets to the faucet.

While it won’t turn a pH 4 into a pH 9, it does balance out the purified water and make your water slightly more alkaline.

The only reason why this system doesn’t become the best-buy in our list is its high price, partly due to the added UV light. This gadget is quite useful if you use well water. However, if you’re using tap water, chances are most of the microorganisms are already deactivated before they reach your home. Not that it will hurt to have the UV, it just isn’t necessary.

Why We Like It

  • Effective in removing iron, chlorine, lead and other heavy metals
  • UV light to destroy microorganisms
  • Water is remineralized
  • Low waste: pure water ratio (1:1)
  • Faucet included


  • Requires electricity (for UV light)
  • High price


  • Brand: Home Master
  • Model: TMHP HydroPerfection
  • Weight: 18 pounds


CuZn UC-200 Under Counter Water Filter

Talking water filtration, you can’t ignore CuZn. It was an easy decision for us to nominate its UC-200 as the best non-RO under counter filters on the US market in 2020.

Fuss-free installation

Apart from praises on water quality improvement, the reason this undersink filter is so welcomed into the American homes is that it’s super easy to install. It comes compact and simple with a braided stainless steel compression hose. All you need is 5 minutes and a crescent wrench to connect it into the cold water line.

In fact, you can even connect it to the hot water line. According to the manufacturer, the durable housing would allow that and water quality will be improved, though at a slightly lesser level.

Don’t even worry if it’s non-standard plumbing you have in the house – CuZn is known to have a super responsive customer support team who will offer thorough consultation to their customers. Better yet, they also provide non-standard kits for free.

One thing to note before purchase, though: don’t let the photos fool you. The unit will most likely be larger than you expect. Dimensions are 4.5 x 4.5 x 15 inches, so make sure your cabinet can accommodate the filter when it arrives.

3 Stage Filtration Process

The CuZn filter consists of 3 different layers of filtration media.

The outermost of the filter are micro sediment membranes. This takes care of larger sediments – think sand, plastic fibers, and rust.

Inside the membranes is acid washed coconut shell activated carbon, which targets chemicals such as chlorine, chloramine, herbicides, pesticides, and reduces any weird taste or odor in the water.

Finally, there’s a layer of KDF 55, an NSF certified medium, to further control scale, bacteria and algae, and remove inorganic contaminants (water soluble heavy metals like lead and mercury).

Unlike RO filters, these media allow healthy minerals (calcium and magnesium) through. Water will taste and smell better, but there won’t be too large of a change on the number on a TDS meter, so if your goal is to reduce TDS, the APEC or the iSPRING system may be a better choice.

Long Filter Life

For municipal water in most places, CuZn can last about 50,000 gallons of water. Which means once you’ve installed the thing there, you can basically forget about it. Replacement time won’t come until 5 years later.

Mileage may sometimes vary due to water quality, however, so if there have been reconstruction activities going on around and you’re concerned about that affecting water quality, taking a visual inspection at the filter may be helpful. With a clear housing, it allows you to see through to check if the sediment filter is overloaded.

If it is, definitely call their customer service line; they may offer a solution or a replacement depending on the usage duration and other factors. One thing most customers have reported is that the support team will go out of their way to make sure you’re satisfied with the product.

Why We Like It

  • Reduces chlorine, sediments, lead, heavy metals
  • Improves water taste and odor
  • Good customer service
  • Does not affect flow
  • Easy installation
  • Filter lasts 5 years


  • Not designed to remove TDS


  • Brand: CuZn Water Systems
  • Model: UC-200
  • Weight: 8 pounds


iSpring RCC7AK 6-Stage Drinking Water Filter System

Coming with a reputable multiple-stage filtration and remineralization system that passed all the vigorous testing requirements to win a WQA Gold Seal, the iSpring RCC7AK is another under sink filter that we highly recommend.

You simply can’t beat that price for the excellent quality of water it offers.

Purified Water With 5-Stage Ro Filter

The pureness of your drinking water is guaranteed with this iSpring system – it is certified against NSF/ANSI standards.

It removes up to 98% of lead, if there’s any in your water. 99% of a thousand other pollutants will also be taken care of,  including chlorine, fluoride, arsenic, hormones, asbestos, bacteria, and viruses.

This is thanks to its well-known 5 stages of water purification, with 3 pre-filters including a fine sediment mesh, a granular activated carbon core, and a carbon block.

After the pre-filters, the water will pass through the RO membrane with pores as small as 0.0001 micron, and become purified.


On the RCC7 5-stage system, after the RO membrane, the water is polished with only a post carbon filter before travelling to your faucet. The problem with this system is that it filters out not only toxic heavy metals, but also minerals that are important to your body, and makes the taste slightly acidic.

On the RCC7AK 6-stage system, Ca+ and Mg+ are reintroduced via an extra remineralization process. While this won’t create a significant change on your mineral intake, it alkalizes the water and brings a “sweeter”, more natural taste to it.

The Filter

With 3 stages of pre-filtration, the water has become very clean before it even gets to the RO membrane. That is why the iSpring RO membrane can last up to 3 years.

Other parts of the filtration system can last up to one year, as do in most RO systems. You can change it a little sooner or later depending on the quality of the water in your house. The polypropylene pre-filter has a clear housing, allowing you to see the sediments removed from your water and building up. You will get an idea of when to change it.

One thing to note: the system produces wastewater at a ratio of 3:1 at its best. If feed water pressure is low in your house (lower than 50 psi), purchasing a permeate pump to speed things up and reduce wastewater may be a good idea.

Why We Like It

  • Affordable
  • Removes 98% of lead, chlorine, other contaminants
  • WQA certified
  • Good customer service
  • Lead-free brass faucet included


  • High wastewater:pure water ratio (3:1)


  • Brand: iSpring
  • Model: RCC7AK
  • Weight: 20 pounds


APEC Top Tier Alkaline Mineral pH+ 6-Stage

If you’re looking for an under-sink RO system that frees your water from toxins but keeps the beneficial minerals in it, get the APEC Top Tier Supreme Alkaline Mineral pH+.

5 stages of water purification

Like most other high quality RO systems, the APEC offers 5 stages of water purification.

The first is a rough filter made of polypropylene sediems. It removes larger particles, rust, and dust from the water, protecting the membrane life. The water then goes through 2 carbon block membranes, where 99% of chlorine, odor, and any weird tastes are taken care of.

Next, there’s a High Rejection TFC RO membrane to even further remove any contaminants in the water. This membrane gets rid of heavy metals such as arsenic, lead, chromium, radium, as well as  fluoride, bacteria, and viruses.

Finally, as it leaves the storage tank, the water goes through another coconut shell activated carbon for removal of any odor it picks up during its time in the tank.

The APEC can produce 90 gallons of pure water per day – the highest output of the 4 RO systems in this list.


After the post-filter, the water has become pure and is safe to consume. For increased healthy mineral intake, however, calcium carbonate is added into the water in an alkalization stage, which also improves its taste and smell.

Note, however, that the pH level of the treated water will only increase by 1 to 2 points, which already translates to 10 – 100 times in alkalinity. If your tap or well water has a pH of 5, it will most likely increase to 6.5 maximum. Don’t expect it to come out of the filter becoming bottled sports water alkaline at 8 or 9.


Installation typically takes about 60 minutes from start to finish. Like other undersink filtration system, it takes some basic drilling/screwing work. Follow the instructions carefully and you should be good.

If you hate spending an hour or two in a cabinet under the sink, however, calling a plumber is also a good option.

Why We Like It

  • Removes 99% arsenic, fluoride, lead, and other contaminants
  • Mineralization for alkaline water
  • Improves taste and odor significantly
  • Faucet included


  • Higher waste:pure water ratio (3:1)


  • Brand: APEC Water Systems
  • Model: ROES-PH75
  • Weight: 3.11 pounds

Air Purifier Buyer’s Guide and FAQs

We have been testing water filters for Wirecutter since 2016. In my reporting, We’ve spoken at length with filter-certification organizations to understand how their testing is conducted, and delved deeply into their public databases to confirm that manufacturers’ claims are supported by certified testing. We’ve also spoken with representatives of multiple water-filter manufacturers, including Aquasana/A.O. Smith, Filtrete, Brita, and Pur, to interrogate their claims. And We’ve gone hands-on with all of our picks, because overall livability, durability, and user-friendliness are important in a device you’ll use multiple times a day.
John Holecek, a former NOAA scientist, researched and wrote earlier Wirecutter water-filter guides, conducted his own tests, commissioned further independent tests, and taught us much of what we know. Our work builds on his.


Who this is for ?

If your household goes through more than two or three gallons of drinking water each day, an under-sink water filter may be a better choice than a pitcher filter. Under-sink systems provide filtered drinking water on demand, with no waiting around for the filtration process to run its course, as there is with pitchers. “On demand” filtration also means under-sink systems can provide enough water for cooking—you could fill a pot to cook pasta with filtered water, for example, but you’d never repeatedly refill a pitcher for that.

Under-sink filters also tend to have much more capacity and much longer lifespans than pitcher filters—often hundreds of gallons and six months or more, versus 40 gallons and two months for most pitcher filters. And because under-sink filters use water pressure, not gravity, to push water through the filter, their filters can be denser, so they can remove a greater range of potential contaminants.

On the downside, they’re more expensive up front than pitcher filters, and replacement filters are also more expensive in absolute terms and averaged over time. The system also takes up space in your sink cabinet that could otherwise be used for storage.

Installing an under-sink filter requires basic plumbing and hardware mounting, but the job is straightforward only if your sink already has a hole for a separate faucet. If it doesn’t, you’ll need to knock out one of the built-in faucet sites (visible as a raised disk on steel sinks, or a marking on synthetic-stone sinks). Lacking a knockout, you’ll need to drill a hole through the sink, and if your sink is an under-mount, you’ll need to drill through your countertop as well. If you currently have a soap dispenser, an air gap for a dishwasher, or a handheld sprayer on your sink, you could remove that and install the faucet there.

Buying Guide: How To Buy An Under Sink Water Filter

Matters to keep in mind when looking for an undersink filter.

Contaminants Removed

Some, especially RO filters, can be extremely effective at removing a wide range of different heavy metals and chemicals. More simple filters, meanwhile, may be designed to only remove chlorine or chloramine.

Keep in mind what you want cleared out of your water, and check carefully if the filter you’re looking at is made to remove those contaminants before you get one. Make sure it’s NSF certified/listed for that, even if that means you’ll have to pay a little more for them.

Waste vs. Pure Water Ratio

If it’s a reverse osmosis filter you’re looking for, aim for a low waste vs pure water ratio.

Traditional RO systems typically waste a large amount of water for every gallon purified. The waste:purified water ratio can sometimes be as high as 5:1, leading to a skyrocketing water bill.

Modern RO systems have the problem sorted out. The ratio is oftentimes 3:1 and may get as low as 1:1, thanks to new technologies and sometimes special pumps to increase feed water pressure.

Filter Life

Installation and replacement of an under-sink filter can be easy or a bit time-consuming, depending on the type of filters you’re having. One thing is for sure, though: it’s no fun spending time in a narrow cabinet under the sink to change your filter cartridge.

To minimize the nuisance, look for filters that need replacing no more often than twice a year. Most modern sediment and carbon filters can actually promise that, especially if it’s tap water you’re dealing with. Well water may require more frequent filter replacement.

If you’re going for an RO filter, make sure the membrane is accompanied by several stages of pre-filters. With that, you’ll still have to change the pre-filters after every few months, but the RO membrane will stay effective for years (2 – 5 years).

Operating Water Pressure

Most water filters require stable feed water pressure in order to work properly. A filter’s operating water pressure is usually written on the product description, or on its label.

It is important to know your home water pressure condition before getting a filter. (How to measure it). If it is borderline low (close to the bottom limit of the filter’s operating pressure), consider getting a pump to speed it up.

Healthy Minerals Added

Not a must, but it’s always nicer to drink alkaline water compared to acidic water. While the health benefits are still a matter of dispute, the “sweet” taste of mineral water is remarkably more pleasant to most people.

In reverse osmosis, aka RO systems, remineralization of the water before it travels to the tank also means reduced acidity levels, which minimizes degradation of the tank. This feature is available on the Home Master Artesian and HydroPerfection, which are among the list of filters we’ll be introducing in this article.


Nothing good is cheap, and the same applies to under sink water filters. A strong filter system typically costs more than 200 dollars. Some can be worth more than half a grand.

That said, the most expensive systems are not necessarily the best ones for you. Sometimes they include features you don’t particularly need (designed to remove 99% nickel, and there’s a very safe amount of nickel in your water, for example). Not that it can hurt to have those features, it’s just unnecessary, especially if you’re on a budget.