Having the best under sink water filter means you’ll have pure, readily available filtered water 24/7. Most are very easy to install since they connect directly into the water line under the sink.

With an under sink water filter, you’ll also be saving them time and money you’d spend buying, loading, and carrying bottles of water.

Best Under Sink Water Filter

There are so many kinds of under sink water filters to choose from, with reverse osmosis being just one of them. To help you with your search, we’ve come up with a list of filters that many users have praised and that we’re sure you’ll like too.

The best under-sink water filters (including the best under-sink alkaline water filters) are the easiest to install. They also last the longest and remove the most contaminants and odors from your water, leaving you with that crisp, satisfying gulp of H2O.

Best Under Sink Water Filters Reviews

1. TMAFC-ERP Artesian Full Contact Undersink RO Water Filter


The TMAFC-ERP Artesian RO filter system is really an amazing filter similar to no other. It features a seven-stage filtration and filtration process, which removes up to 99% of the most stubborn contaminants, including chloramines, heavy metals, and traces of pharmaceuticals.

Using a catalytic carbon filtration media, this filter is perfect for those who require ultra-pure water balanced with minerals. With a 75 GPD production and 1:1 waste water ratio, you can’t get any better than this.

Max Efficiency

This filtration system does an even better job than most RO systems to provide you with the best water. It features seven stages of filtration and enhancement, which eliminates virtually all contaminants in your water.

Moreover, the non-electric permeate pump reduces waste water by up to 80%, doubling pure water production compared to other models. The filters required also last a very long time (at least 2000 gallon capacity) and can be easily replaced once a year.

Manufactured in the USA, it’s also designed to provide cleaner water than most by eliminating ‘TDS creep’ over time.

Water Enhancement

In addition to having water free of chemicals and debris, many people want water that’s actually good for their health with minerals required by our bodies.

This filter accommodates that need with Full Contact technology that adds 30-60mg/l calcium and magnesium minerals twice during the filtration process.

Most other RO systems produce slightly acidic water, which can negatively impact your storage tank and decrease water quality.

Adding just a touch of minerals using this filter system can provide you and your family with water that nourishes.

Innovative Design

It wouldn’t be the best if it weren’t built using the most innovative modular design. The way it’s set up helps prevent common problems like canister filter housing leaks, slow flow, high waste, and acidity.

This model lets you change the filter and the housings once a year so that you can avoid the problem of sedimentation and biofilm formation in those canisters, which can lead to expensive repairs.

Since you only need to change your filter and canister once a year, it’s still a great bargain.

Additional Specification

  • Best For: Ultra-pure Water
  • Color: White
  • Brand: Home Master
  • Feed Water: 40 – 90 PSI
  • Item Weight: 14.5 Pounds

Why We Love It

It’s a very efficient and long-lasting model that meets all the reverse osmosis requirements and exceeds expectations. Worth the price for how well it works!

Keep In Mind

It’s quite expensive, but you’ll save more in the long run by not having to buy any water bottles and reducing the amount of wastewater from your RO system.

2. APEC WFS-1000 – 3 Stage Under-Sink Water Filter System


This is the best value you can get for an under-sink water filter, which comes with a 3-stage system targeting chlorine, odors, and contaminants in your tap water.

One of the major things about this system is that all the parts are made and assembled in the US to rest assured about the quality. The filters last for around a year and clean your water instantly, for faster and more efficient water flow.

Unlike RO systems, it also doesn’t produce any waste water.

Powerful 3-Stage System

This system is similar to an RO system but without the extra filtration steps and waste water production. It’s expertly engineered to last a long time and provide you with great-tasting pure water.

The first stage consists of a 10” high-capacity polypropylene sediment filter, which removes dust, rust, and particles. The second stage is a 10” premium extruded carbon block filter chlorine, taste, odors, VOCs, and most chemicals.

The third and final stage of this best under sink water filter is another extruded carbon block for further removing wastes.

No Waste

Most RO systems at least have a 1:1 waste to pure water ratio. This means you’ll still be paying for a lot of the water you can’t actually use.

With this high-performance, low-cost best under kitchen sink water filter, you’ll be enjoying direct filtration with no waste water for years to come.

Each filter also lasts a year or longer, giving you the benefit of saving both money and the environment.

Proceeds to Charity

The APEC manufacturers know what it’s like not to have access to pure, clean water, which should be a right for everyone.

That’s why it’s put together a water donation program with a percent of the proceeds going to charity for every purchase. The mission at APEC is to ensure as many people as possible enjoy the water that’s good for health.

Additional Specification

  • Best For: Efficient Water Flow
  • Color: White
  • Brand: APEC Water Systems
  • Feed Water: 20-85 psi
  • Item Weight: ‎14 pounds

Why We Love It

This filter system works really well and is completely made in the US, so we can be sure that it’s manufactured by those who stand by their product. Requires a filter change only once a year and does not produce any wastewater.

Keep In Mind

It doesn’t really do anything for the TDS, so we suggest the first filter if you’re concerned about that. Also doesn’t add any minerals, so you’re left with ‘cleaned’ water.It’s quite expensive, but you’ll save more in the long run by not having to buy any water bottles and reducing the amount of wastewater from your RO system.

3. Filtrete Advanced UnderSink Filtration System


Filtrete’s Advanced Quick-Change Filtration System removes much of the unwanted stuff from your drinking water, including microbial cysts, chlorine taste, and odor, as well as various particulates.

Its claims are also backed by demanding NSF certifications for Standard 53 and 42. It also takes no delay in providing you with the finest water, maintaining full water flow at 2.25 GPM, and has a high capacity of 2,000 gallons. You can now quench your thirst in almost no time.

Reliable Function

Filtrete’s interchangeable and upgradable Undersink Quick-Change system is definitely worth the try.
Once you do, you’ll be happy that you found a filter that can take care of your water’s microbial cysts, chlorine taste and odor, sand, soil, rust, and other unwanted matters. There is also no need for a dedicated faucet so you can easily connect it to your kitchen or faucet.

The installed filter will last for a good six months working at its full potential.

Effortless Installation and Maintenance

This is one of the easiest and mess-free installations you’ll ever do. The only thing you’ll need is an adjustable wrench and screwdriver to secure the parts.

The process takes no more than half an hour, even for the novice.

Even though it’s highly recommended that filters be changed once every six months, the system itself can last for many years.

Full NSF Certification

The fact that this filtration system is NSF certified for both Standard 42 and 53 says a lot in and of itself.

The first standard is for systems designed to reduce aesthetic and non-health-related contaminants that still make your water taste quite nasty. They shouldn’t be present in the water that you drink.

This filter takes care of those odors and particles so that you can enjoy the ‘taste’ of your water. Standard 53 is for those filters that also remove specific health-related contaminants in public drinking water.

Those that certify remove a significant amount of those contaminants for fresh and revitalizing water.

Additional Specification

  • Best For: Easy to Install
  • Color: White
  • Brand: Filtrete
  • Flow Rate: 7.57 Litre per minute
  • Item Weight: ‎‎3.08 pounds

Why We Love It

Removes much more than just chlorine while maintaining full water flow. Also very easy to install and can fit under any available faucet in your home.It’s a very efficient and long-lasting model that meets all the reverse osmosis requirements and exceeds expectations. Worth the price for how well it works!

Keep In Mind

The filters are said to last for six months, but many people report that they may not last as long.It’s quite expensive, but you’ll save more in the long run by not having to buy any water bottles and reducing the amount of wastewater from your RO system.

4. ISpring RCC7AK UnderSink Reverse Osmosis Filter System


Comparable to a ‘smart’ filter, the iSpring UnderSink reverse osmosis filter system has all the features you’d look for in the best under sink alkaline water filter.

From a multi-layer filtration system removing almost anything bad in your water to the quick-connect fittings for easy installation, you’ll love what it has to offer.

One very cool feature is the reinforced transparent first-stage housing, which allows you to see the contaminants as your water travels from first to second stage filtration, so you know it’s working.

‘Hyper-Effective’ Filtration

This is one under-sink mounted filter that does it all, from softening your water with healthful minerals to removing up to 99% of over 1,000 contaminants, including lead. Enjoy water that’s also free from chlorine, fluoride, arsenic, hormones, asbestos, bacteria, and even viruses.

Moreover, the filters last the longest of their kind and feature high-quality six-stage filtration, with each progressively removing the smallest (5 microns) pollutants in your tap water.

The first filter is a PP sediment filter, which removes the larger contaminants and protects the RO membrane from degradative chlorine and chloramines. The next two pre-filters consist of a carbon KDF (GAC) filter and a carbon block (CTO) filter, removing larger molecules.

The reverse osmosis membrane is said to remove particles as small as 0.0001 microns allowing only water molecules to pass through. Another GAC filter polishes your water before it gets re-mineralized.

Alkaline Remineralization

Remineralization improves the taste of your water and also makes it better for your well-being. The sixth stage consists of an alkaline regionalization filter that uses natural mineral stones as its filtration media.

The red mineral stone used in the AK filter doesn’t just add calcium. It also adds various other minerals naturally found in spring water, including magnesium and calcite, directly neutralizing the pH. This makes the RCC7AK stand out from others.

Cutting-Edge Design

One use of this filter, and you’ll understand that it was created with customers in mind. Featuring a feed water adapter that fits both 1/2” NPT and 3/8” COMP water lines, 4-color tubings, spare fittings, and O-rings, it comes with everything you need for a successful and easy installation.

The first pre-filter housing also comes transparent so you can see your filter working. The filtration system itself was designed for the finest micron layered protection, which means that the five filter layers are arranged so that only the smallest particles reach the RO membrane, making it last longer than most other systems.

Additional Specification

  • Best For: Performance & Durability
  • Color: White
  • Brand: ISpring
  • Feed Water: 45 PSI – 70 PSI
  • Item Weight: 20 Pounds

Why We Love It

It removes a significant amount of contaminants most other water filter systems miss. It also restores minerals that are removed from the intense filtration and come with a solid brass faucet.

Keep In Mind

Higher than 1:1 waste to pure water ratio (3:1) and has a narrow feed pressure range of only 45-70psi. The product requires Prop 65 warning (for PVC) but is BPA-free.

5. Aquasana 3-Stage Max-Flow Under-Sink Filter System


What’s not to love about the Aquasana 3-stage max-flow filter system? It features a high filtration rate faster than almost anything we’ve seen in the market and reduces 99% of over 65 contaminants, including lead, mercury, asbestos, and pesticides.

Three NSF standards also back it: 42, 53, and 401 and comes with a choice of two faucets, chrome, and oil-rubbed bronze. One incredible thing about the filters it uses is that one Aquasana is said to last as long as 20 gravity-based filters, for fewer replacements and huge savings.

Amazing Contaminant Reduction

With this filter, you’ll be able to reduce up to 99% of over 65 contaminants in your tap water, including lead, mercury, and asbestos. The entire system is also certified by NSF for three standards (complete certification).

The Claryum filtration technology enables filtration without touching upon the naturally beneficial minerals in the water. The required minimum feed water pressure of 20psi also lets it work well with virtually any under-sink water line.

You can trust in this upgraded technology with a 20-micron pre-filter, activated carbon, and catalytic carbon to provide you with water. You won’t have to think twice about drinking.

Full-Range NSF Certification

While it’s already great that a filter system comes with some form of NSF standard certification, this one comes with three!

The NSF certification 42 means that we can take it for its word for removing chlorine taste, odor, and particulates.

Certification 53 includes cryptosporidium, lead, volatile organic chemicals (VOCs), and asbestos. Thirdly, certification 401 means your water will be clear of herbicides, detergents, ‘emerging’ pesticides, and pharmaceuticals.

Economical Productivity

This system is highly upgraded from a 600-gallon filter capacity to 800 gallons to last longer and require fewer changes.

In fact, the filters work so well that Aquasana claims one of their filters can last as long and work as well as 20 leading gravity-based filters.

The flow rate is unquestionably higher, moving from a 0.5gal/min in the original model to 0.72 gals/min in this latest version. It’s definitely a cost-effective choice.

Additional Specification

  • Best For: Higher Capacity
  • Capacity: 800 Gallons
  • Brand: Aquasana
  • Feed Water: 20-80 psi
  • Item Weight: 7 Pounds

Why We Love It

One of the fastest filtration rates we’ve seen also does a great job at removing those pesky pollutants. It also has three NSF certifications, while many have only two. Retains minerals in your water.

Keep In Mind

It doesn’t really go into much detail about its BlueTooth technology other than it helps to track how well your filter is doing and when to replace it (which doesn’t really require BlueTooth, in our opinion)

6. Aquasana 2-Stage Under-Sink Filter System

Aquasana 2-Stage

The Aquasana 2-stage system also removes 77 of the most common and difficult to detect pollutants in your tap water.

With Claryum technology, you can get rid of what you don’t want while keeping what you need. This filter system is also very easy to install and replace filters for when needed to top it off.

Superior Effectiveness

This filtration system removes more pollutants and contaminants than you can name from memory.

These include lead, mercury, asbestos, herbicides, and various pharmaceuticals. The removal happens without using any chemicals (which defeats the purpose) and doesn’t produce any wastewater.

It’s only ten cents per gallon, water that’s cheaper and purer than you’d get anywhere else without the use of a high-quality under-sink water filter.

Top Reliability

In addition to just the filter system, you also get your own 100% lead-free faucet with a choice of finish to match your kitchen.

The set comes with everything you need to install your 2-stage Aquasana system yourself. It further comes with full system NSF certifications for standards 42, 53, 401, and +P473.

The fourth certification indicates that it meets the strictest requirements for material safety and is contamination-free.

Enhanced Water with Claryum Technology

To filter out harmful particles and chemicals to completion, filter systems require both activated and catalytic carbon, which is what you’ll get here.

The first removes organic chemicals like pesticides, herbicides, and VOCs, while catalytic carbon reduces chlorine and chloramines.

The ion-exchange mechanism further filters out heavy metals that are toxic to your body. Sub-micron filtration in these steps captures cysts and other bio-particles.

Additional Specification

  • Best For: Great-tasting Water
  • Capacity: 500 Gallons
  • Brand: Aquasana
  • Feed Water: 20-80 psi
  • Item Weight: 0.05 Pounds

Why We Love It

A kindly affordable filtration system that uses sub-micron mechanical filtration as well as activated carbon and ion-exchange. Also very easy to install and replace filters. Complete certification and comes with a faucet.

Keep In Mind

It’s harder to install if you have a 3/8” tubing water line and may affect your water flow in that case.

7. FrizzLife Under-Sink High Capacity Filtration System


There’s no fuss needed about choosing FrizzLife as your go-to under-water filter. It’s the ideal filter for anyone who wants to save money while benefiting from high-quality filtration.

With versatile connections to both 3/8” and 1/2” feedwater lines, it can connect simply to your refrigerator and ice maker as well as under the bathroom and kitchen sink.

You’ll be especially glad to know each cartridge lasts for 1,600 gallons, so you won’t have to replace it as often. The flow rate is also spectacular at 2.00 GPM (40 psi).

0.5 Micron Precise Filtering

Frizz life’s first filtration stage uses a 5-micron precision sediment filter cartridge to reduce many of the larger particles from the water, including sand, silt, and rust.

The block carbon filter cartridge then removes anything you can’t see with 0.5-micron precision.

Up to 99.9% of lead, chlorine, and 56 other contaminants leave your water, providing you with water that’s deliciously pure and wholesome.

More of What You Need

This filtration system works by targeting the harmful chemicals and particulates in your water to affect ppm (TDS).

The number of dissolved solids remain the same or around since the essential minerals are left behind. These include calcium, iron, sodium, magnesium, zinc, and phosphorus, many people don’t get enough of in their food. Your body needs these minerals to thrive.

Anyone Can Install

With the FrizzLife water filter, have no worries about whether you can install the product. The quick twist-in installation allows you to complete the task in under three minutes so you can enjoy all that this filter has to offer almost instantly.

The filter cap’s auto shut-off design makes sure that the water supply is shut off, so you don’t have to do it each time you replace the filter manually.

You will also just need to replace the core part of the filter cartridge rather than the entire thing. Plus, the filter costs less than most brands, so it’s a win-win choice.

Additional Specification

  • Best For: Great-tasting Water
  • Flow Rate: 2 Gallons Per Minute
  • Brand: FRIZZLIFE
  • Feed Water: 60 psi
  • Item Weight: 4.2 Pounds

Why We Love It

This model takes easy-to-install to a whole new level so anyone can use this system conveniently. It’s also compatible with both 1/2” and 3/8” water lines and works optimally to remove the unwanted stuff from your water—cheaper and long-lasting cartridges.

Keep In Mind

It doesn’t change the PPM (TDS meter reading), but that’s because it leaves all the good minerals in your water untouched. Hard to install in tight spaces.

8. CuZn UC-200 Under-Counter Water Filter


This is the best under kitchen sink water filter (or bath sink), which easily fits a 3/8” water line for optimal water taste and quality. An important thing about this filter is that it is also bacteriostatic and removes organic compounds, including living bacteria and some viruses.

It also selectively purifies the water, maintaining the original mineral content of your water. However, it doesn’t work as well if you have tough water, to begin with.

The best thing is once you have it installed, you can just ‘set it and forget it’ for a whole five years, as it requires virtually no maintenance.

Competitive Value

We believe that the CuZn ultra-high capacity filter really outruns its competitors when pricing and quality. What you get with this filter is available in other filters, but they are often much more expensive and aren’t backed by NSF certifications like this one is.

In addition to being among the top in terms of what it can remove, it also remains bacteriostatic, which is good considering that it’s meant to last for a while. Enjoy the health-giving benefits of pure water in the comfort of your own home faucet.

Advanced Contaminant Removal

Only the best filter membranes are used in this CuZn model, beginning with the micro-sediment membranes, which remove anything that’s 5 microns in size or larger.

The next step combines a patented KDF-55 Filtration media and virgin acid-washed catalytic coconut shell carbon filtration media that passes both NSF standards 42 and 61.

Both harmful organic and inorganic debris is removed from the water, so all you have is pure, crystal-clear water with some minerals (including ‘hardness minerals’) left behind.

Use a DPD#1 chlorine test strip to see for yourself why this system ranks among the best.

Unrivaled Capacity

It’s common to think that a filter lasting one year is ‘good enough,’ and it’s true that systems lasting longer sound too good to be true.

Then comes the CuZn UC-200, which will last you five times longer than the leading brand of under-sink water filters. To work optimally, it is suggested that you replace the filtration model every five years or 50,000 gallons, depending on what comes first.

Additional Specification

  • Best For: Log Lasting
  • Capacity: 50K gallon
  • Brand: CuZn
  • Feed Water: 25 to 75 psi
  • Item Weight: 7.89 Pounds

Why We Love It

Water (and ice cubes) coming out from this filter looks crystal clear and tastes a lot better than tap water. The set-up is also easy enough for anyone to follow.

Keep In Mind

For use with municipal water only, not suitable for private well water. It also doesn’t soften the water (so it doesn’t deal with hard water issues or replace minerals). Uses 3/8” fittings.

9. Woder 10K-Gen3 Direct Connect Filtration

Woder 10K-Gen3

The Wonder line is considered to be one of the most well-known filter systems in the US. Its legacy is built by delivering the highest quality products at an affordable price.

Designed to be the best under the kitchen sink filter system (or bathroom faucet), it will provide you with the best tasting water from your cold water line. Installed using 3/8” female compression by 1/4” standard pipe thread and removes up to 99.9% of disturbing pollutants that shouldn’t be in anyone’s drinking water (lead, asbestos, etc.). Enjoy tap water as healthy as spring water today.

Enduring Build

Wonder’s legacy under-sink filtration system lasts for a very long time, at least 10,000 gallons or 3 years, when used regularly.

It connects directly to your cold water line for drinking and cooking uses. All the essential minerals are left behind, so you have water as nature intends it to be.

It works even better than reverse osmosis by using micro-particles to filter out impurities. This makes the Woder filter last so much longer than many of the other models.

Worry-Free Installation

Sometimes, installing a new water filter means you also have to pay a professional to do the installation. With the ‘direct connect’ hoses that fit standard 3/8” valves under most sinks and easy to follow instructions, you’ll be able to install the system yourself, even if you’re a novice.

“Tap Water as Healthy as Spring Water”

One fascinating fact about this system is that what comes out of just one filter is comparable to 75,600 mineral water bottles.

When you think of all the spending and plastic footprint you’d be able to avoid, this really is a wonderful product. It also helps eliminate 99.9% of lead, heavy metals, chlorine, chromium mercury, VOCs, and more that are still found in municipally treated water.

Essential minerals are left behind to improve the quality and taste.

Additional Specification

  • Best For: Affordable Price
  • Capacity: 8,480 gallon
  • Brand: Woder
  • Feed Water: 75 psi
  • Item Weight: 2.82 Pounds

Why We Love It

An affordable selective filtration system attracts contaminants while leaving a good amount of calcium, potassium, and magnesium in the water. Lasts six times longer than many leading brands.

Keep In Mind

It cannot be used with softened or hardened water or with well water. Slows down your flow rate a bit. Fits 3/8” lines only.

10. Culligan US-600A Under-Sink Drinking Filtration System


Culligan is another trusted brand for any filtration system, as it’s been around for many decades.

The US-600A under sink filtration system reflects what the company stands for and comes in a compact size that will fit under your sink no matter how much (or how little) space you have.

It also comes with a basic filter that can be swapped out for more advanced types of filters that take the lead and pesticides out of your water—the spend thrifter’s choice.

Smooth Flowing Water

This thrifty yet hard-working filter system uses granular activated carbon to remove chlorine, odors, and particles from your drinking water.

It runs at a rate of one whole gallon per minute, so you don’t have to wait long to quench your thirst.

There’s also a huge operating pressure range from 30-125 psi, so it’ll be compatible with your water line even if your pressure is higher or lower than average. Get a year’s worth of all the water you’ll want with each filter.

Interchangeable System

While this system comes with a basic D-20A filter for 89% chlorine taste and odor removal, you can switch it up any way you like with other Culligan filters.

The D-30A filter is advanced and further removes chlorine up to 99%. D-40A’s premium filtration works to reduce the aesthetic taste of water and NSF certified to remove nominal particulate class I matter (Standard 42) and cysts, turbidity, mercury lindane, atrazine, and asbestos (Standard 53).

Lightweight and Compact

Comparably lightweight compared to most under-sink water systems, weighing only 1.75 pounds. It also comes with quick-connect fittings (using 3/8” inlet/outlet) for simple, few-minute installations and filters replacement.

Additional Specification

  • Best For: Drinking & Cooking
  • Capacity: 1000 Gallons
  • Brand: Culligan
  • Feed Water: 60 psi
  • Item Weight: 1.74 Pounds

Why We Love It

Compatible for health-conscious individuals who are on a budget and who may have little space underneath their sinks. Instantly changes the taste and appearance of your water. The system also enables interchanging with more advanced filters.

Keep In Mind

 Each filter lasts only 1,000 gallons, which is an intermediate in terms of capacity. The most basic only deals with chlorine taste and odor (89%) but great for the price.

Under Sink Water Filtration System Comparison

NameBest ForColor/CapacityBrandFeed Water/FlowItem Weight
TMAFC-ERP Artesian Undersink FilterUltra-pure WaterWhiteHome Master40 – 90 PSI14.5 Pounds
APEC WFS-1000 Under-Sink FilterEfficient Water FlowWhiteAPEC Water Systems20-85 psi14 pounds
Filtrete Advanced UnderSink FiltrationEasy to InstallWhiteFiltrete 7.57 Litre per m.‎‎3.08 pounds
ISpring RCC7AK UnderSink FilterPerformance & DurabilityWhiteISpring45 PSI – 70 PSI20 Pounds
Aquasana Max-Flow Under-Sink FilterHigher Capacity800 GallonsAquasana20-80 psi7 Pounds
Aquasana Under-Sink Filter SystemGreat-tasting Water500 GallonsAquasana20-80 psi0.05 Pounds
FrizzLife Under-Sink Filtration SystemGreat-tasting Water-FRIZZLIFE60 psi4.2 Pounds
CuZn UC-200 Under-Counter FilterLog Lasting50K gallonCuZn25 to 75 psi7.89 Pounds
Woder 10K-Gen3 FiltrationAffordable Price8,480 gallonWoder75 psi2.82 Pounds
Culligan US-600A Under-Sink FiltrationDrinking & Cooking1000 GallonsCulligan60 psi1.74 Pounds

Best Under Sink Water Filtration System – Buying Guide

If you still want more guidance on which under-sink water filter to buy, we’ve got you
covered. Starting from the capacity and working your way to each model’s neat details, we will show you what makes certain filters the best of their kind.

Best Under Sink Water Filtration System

Whether you’re looking for the best under sink alkaline water filter or best under kitchen sink water filter, here are some guidelines to make sure you’re leaning towards the right ones.

Feed Pressure Ranges

The feed pressure range tells you what water pressure your filter system will accept.

Most households have an average pressure of around 60-100ppm for water going through their water lines, but yours can be more or less.

Finding out your pressure will determine which models work best for you as some can handle high pressures while others have quite a narrow range.

Neither is better than the other, but generally, those that can handle a higher feed pressure will also be less likely to impede your water flow.

NSF Certification

One way to make sure that your filtration system does what it says it will is by checking for NSF certification.

To qualify for such certification, manufacturers have to submit their products under a great deal of testing and finally gain approval.

These tests determine whether the filters really filter out chlorine taste and odor for aesthetic improvement (standard 42) and health-degrading pollutants such as harsh chemicals, pathogenic bacteria, and more (standard 53).

Additional standards may apply depending on the product.

Waste To Pure Water Ratio Vs. No Waste Water

The best RO systems that we’ve seen yield a 1:1 waste water to the pure water production.

However, at the end of the day, that’s still some water being wasted.

If that doesn’t roll well with your utility bill or you’re looking to save even more money, you’ll have to get a carbon block filter that doesn’t produce any wastewater.

These systems may not be RO, but they can work comparably well and save you lots of money.

Permeate Pumps

The importance of a permeate pump is helping RO systems to reduce water waste cannot be overstated. Rather than increasing the system’s speed or pushing the water through, the pump gets at the heart of the problem to double the filter’s efficiency. The first step is storing the reject water, which gets used by the pump as energy, pushing permeate (clean drinking water) from the RO membrane through the inlet and propelling it to the storage tank. This means the ‘waste water’ isn’t really wasted but used as energy to make your system more efficient!

Water Refinement

The best RO systems for your home are the ones that add minerals back into the water after it has been cleaned. However, this process is not needed in infiltration systems that rely on other mechanisms besides RO. For example, regular carbon block technology may use Claryum technology. This filtration technology allows harmful particles to exit the water while leaving the naturally beneficial minerals untouched.

Total Capacity

There are a few ways to measure a filter system’s capacity. The first is by looking at each filter’s capacity, which can be replaced while the system itself remains intact.

Those that promise around 500-1000 gallons per filter are really great. The next is by looking at the system itself, which should last for five years or more.

Another important thing to look at is the GPM or gallons per minute and cost per gallon, which should be a number you get for all the filters you want to compare.

The best are around 2.25-3GPM and 8 cents per gallon.

Versatile Fittings

Many filters fit only 3/8” water lines, so it’s important to check and make sure you have the filter that fits your water line.

We mentioned a couple of models that fit both 1/2” NPT and 3/8” COMP water lines. This versatility level may be very important for those who don’t have a 3/8” standard water line.

Frequently Asked Questions and Answer

Why don’t many of the under-sink filtration systems change the PPM (TDS reading)?

Many of the under-sink water filtration systems you see in our review don’t reduce the TDS reading because they only remove the ‘bad stuff’ like bacteria, sediment, and harmful chemicals.

They leave behind minerals that are good for your bodies, such as calcium, magnesium, and phosphorus.

Typically, these are also measured as dissolved solids due to their ionic nature, which is what is measured with a TDS meter.

Why is chlorine in our water in the first place? Shouldn’t it be removed?

Even though it makes the smell and taste of your municipal water less than appealing, chlorine is quite an effective disinfectant that kills many of the pathogens in your water before it reaches you.

The job of water filters then is to reduce the chlorine and pathogens further and take away those unpleasant odors.


When the market is filled with different filters to choose from, it can definitely be hard to find one that you like best and works for your needs.

We are here to help you find what you need for now and for years to come.

The TMAFC-ERP Artesian Full Contact Water Filter system gives you the best RO filtration you can find, probably anywhere else. It even has a non-electric permeate pump, which works to save water without costing you a penny. It also restores all the minerals lost in your water, so you really get a nice, clean, and healthy glass of H2O with each use.

The best value comes with the WFS-1000 APEC filter, which isn’t RO but handles quite high pressures and tops most other filters in terms of quality and flow. It’s also very cost-effective, and you’ll still enjoy many of the benefits you have with RO.