9 Best Under Sink Reverse Osmosis Systems

Looking for a way to enjoy great tasting purified water for a low price?

Then, RO filtration system is the solution for you to get the ultimate filtration and purified water.

The purifying RO system provides safe and tasty drinking water by reducing a broad range of potentially harmful contaminants. It also saves you money by eliminating the high cost of bottled mineral water.

However, the under-counter RO system is great as it doesn’t take up any countertop space and remains hidden out-of-sight. It provides drinking water at a single faucet.

But shopping for the best under sink reverse osmosis is a bit different than purchasing other filtration systems. So we want you to be well-prepared for this daunting task.

Keep reading our under sink reverse osmosis reviews to find out the 9 sought –after models available.

9 Best Under Counter Reverse Osmosis Systems – A Quick Comparison of Our Favorites

Here’s a quick comparison chart showing the essential specs of our 9 reviewed models. Consider them when making a quick purchase.

Best Under Sink Reverse Osmosis Systems

A lot of available options for RO systems may confuse you when you are planning to buy one.

Buying a RO filtration system is an investment, so you need to be extremely sure which one will suit your immediate and long-term needs.

After conducting thorough research and testing out several systems, you have short-listed 9 top-rated models.

Discover them below!

1. APEC Water System ROES-PH75 Top Tier Essence Series

APEC ROES-PH75 Essence Series

APEC’s RO system delivers refreshing taste water that is more distinctive than any other brand. And ROES-PH75 from Essence series is no different.

Designed, engineered, and assembled in the USA, this model guarantees supreme quality and safety for drinking water.

For those who don’t know, APEC is America’s no.1 rated water filter brand. It has 20 years of success guaranteeing a trouble-free, long-lasting system for pure drinking water.

The APEC-Top Tier 6-Stage RO system offers unlimited great tasting water right at home without much effort for people who prefer mineral water.

So, what makes this so special?

The system’s qualities are superb, to say the least. It uses the most effective filtration technology in the industry.

A commitment to providing stress-free usage with maximum satisfaction!

APEC ROES-PH75 has been tested and certified to the highest standard in the industry. WQA Gold Seal guarantees the highest contaminants removal rates for providing you the purest water possible.

No added additives!

Importantly, it provides essential alkaline water without any additives added. Its high-purity pH+ alkaline filter uses a premium cartridge. It safely and efficiently raises the pH level of water to provide purified alkaline water.

In the first stage, the high-capacity sediment filter removes rust, dust, and particles. It also extends the service life of the RO membrane and the system.

Super-efficient to remove maximum possible chemicals and chlorine in drinking water!

The effectiveness of the uniquely designed APEC double Carbon blocks is unparalleled. It removes unpleasant tastes, odors, colors, and cloudiness.  VOCs and other common chemicals are also filtered at these stages. (2nd and 3rd stages)

Notably, the Carbon Block surface is extremely large that maximizes contact time to ensure water purity. It also multiples the lifetime of the filters and membranes.

TFC reverse osmosis membrane removes up to 99% of TDS and other contaminants, leaving perfectly clean & safe water. (Stage 4)

Stage 5 involves removing any possible residual and taste from water by advanced coconut shell carbon filter.

Finally, to ensure the highest-quality mineralized drinking water, the mineral cartridge adds calcium carbonate. It neutralizes acidity and increases water alkalinity. (Stage 6)

It’s worth noting that the system can filter 90 gallons per day @ 60 psi. The pre-pressurized tank can store 4 gallons of water.

Of course, it works well with municipal and well water systems.

Installation is a snap!

It comes with all parts for hassle-free installation. The installation instruction and videos are included for an easy DIY experience.

And you know what else?

It doesn’t require any extra lock clips to seal the leak. Thanks to its leak-free, high-quality quick connect fittings.

A 100% lead-free, modern design faucet is the safeguard to your health. The included JG tubing is food-grade, and FDA approved. All other parts are also lead-free to ensure contamination-free, safe, pure water.

The manufacturer gives two years of extended manufacturer warranty with registration.

So, are you ready to enjoy unlimited healthy and great tasting water right at home for drinking and cooking?


  • Well-built and durable
  • Ideal for city and well water systems
  • Very efficient
  • Great water taste and quality
  • Convenient to use
  • Great flow rate
  • Quick and easy installation
  • Good Instructions for DIY


  • It included several filters that require replacement at different times.

2. Home Master TMAFC-ERP Artesian Full Contact Undersink Reverse Osmosis System with Permeate Pump

Home Master TMAFC-ERP

Home Master TMAFC-ERP is a smarter choice for picky water drinkers. It is a very reliable system that produces extremely pure and great tasting water.

Is it really that good?

Featuring the innovative design and patented Full Contact Technology, this model gives you a promise of unmatched performance.

Filtration, purification, and enhancement- exceptional water purity!

TMAFC-ERP Artesian is among the few RO systems that use seven stages in the process. It removes up to 99% of water contaminants.

The carbon pre-filters has the most advanced and powerful catalytic filtration media that treat stubborn contaminants.

It does not corrode the tank as other RO systems do!

The best thing about this system is its patented Full Contact remineralization technology that prevents storage tank degradation. It balances the pH level of water at two different points of the process to prevent storage tank degradation.

At both points, small amounts of magnesium and calcium are added to the water. This makes the water slightly alkaline. The resulting water is great-tasting, healthy without the acidity.

It’s worth noting that in the conventional RO system the debris filtered through the RO membrane accumulates in the canister. It eventually weakens the housing. As a result, it starts leaking. But this is not the case with the Home Master TMAFC-ERP system.

The modular all-in-one design is an innovative way to solve this problem of the canister filter housing. This design combines the filters in housing that makes it easy to change.

Faster flow rate and better water efficiency!

A non-electric permeate pump enhances the unit’s efficiency. It enables the production of 75 GPD and flows rate. It also reduces the water wastage to a ratio of 1:1.

The device comes with a Fast Flow RO kit, which uses high-flow components larger fittings, and tubing. This, combined with the power of the permeate pump, ensures the fast water flow rate to the faucet. Notably, this flow rate is nearly double when compared to traditional RO systems.

The filters of this unit last longer than that of conventional RO systems. It only requires a filter change for every 2,000 gallons or once a year. Conveniently, the push-in fittings and modular design ensure a quick and tool-free filter change.

The unit comes fully assembled with filters and RO membranes. What’s more, the package includes a storage tank, chrome RO faucet, and all other parts that you will need for a simple DIY installation.

Most importantly, all the parts of this product meet NSF standards for water purification performance and materials safety.

Finally, this bad boy comes with a whopping five-year limited warranty from the manufacturer.

Buy this under sink reverse osmosis water filter system today that brings solutions — not problems.


  • Reliable and easy-to-use design
  • Designed for well or city water
  • Fast and efficient annual filter change
  • Increased water production by up to 50%
  • Reduced water waste by up to 80%
  • High water flow rate
  • Excellent water saving ratio
  • Made in the USA


  • Some users have complained the images in the manual is confusing with the instruction.

3. iSpring RCC7AK 6-Stage Reverse Osmosis alkaline Water Filter System

iSpring RCC7AK

If you are on a budget, the iSpring RCC7AK is the best RO filter to fit your bills.

For a 6 stage filtration system, its price is competitive. In fact, it’s hard to find a home RO system like this under a certain price threshold.

Don’t make mistakes, thinking it’s a basic unit. RCC7AK is an advanced RO drinking water filter system with a lot going for it in terms of features. It’s unequaled in quality, performance, and durability.

This 5-stage unit delivers you more natural taste water than a regular 5-stage RO filter.

In the first stage, the PP sediment filter removes sediments, rust, dirt, sand, and particles.

The GAC filter (stage 2) features loose carbon that effectively flushes out large contaminants from water.

Next, the CTO carbon block filters out mineral deposits and smaller particles.

Thus, the GAC filter and a CTO filter provide additional protection for the sensitive RO membrane.

The RO membrane of this unit is a thin-film composite semipermeable that provides a mind-boggling filtration competence of up to 0.0001 microns. It can produce bottled quality drinking water up to 75 gallons per day.

The post-carbon removes any possible residual from water that changes its taste and odors.

Finally, the calcite rich pH filter increases water alkalinity and gives back healthy minerals to make it more ideal for consumption.

The first stage of housing is transparent that lets you observe the iSpring’s filtration. Additionally, you can easily inspect the filter’s life.

The compact footprint of this unit makes it perfect to fit under the sink cabinet.

Simple installation process!

The color-coded quick fitting connections and simple instructional video are helpful for iSpring reverse osmosis DIY installation. All necessary parts come included for DIY installation.

Most importantly, all the components are of premium quality and independently tested and certified against NSF/ ANSI standards.

We applaud the European style high spout solid brass faucet. Its nickel finish and quarter turn handle looks elegant and fits seamlessly to compliment kitchen design.


  • Reliable and ultra-safe
  • Optimal protection against over 1,000 harmful contaminants
  • Superior Filtration Performance
  • Proven premium quality and high performance
  • Bottled-water quality, great-tasting water
  • Filtered water to waste water ratio (w/ Tank) 1:3
  • Industry-leading customer support
  • Affordable price


  • Installation may take longer than it should for a DIY.

4. Brondell RC100 Circle 4 Stage Under Sink Reverse Osmosis Water Filtration

Brondell RC100 Circle

Brondell RC100 is water savings, power savings, and space savings- all in a beautiful, simplified design.

With this high functional RO system, keep your family healthy by easily removing harmful contaminants from your water.

Healthy, clean, and tasty water is at your fingerprint!

Its four separate advanced water filters work together that dramatically reduces industrial and harmful chemicals from tap water. 

It removes a great percentage of contaminants, including chlorine, fluoride, arsenic, VOC chemicals. It also eliminates TDS creep, leaving readings of below 10ppm on the TDS meter.

Importantly, the large surface of the carbon filters maximizes their contact with water to purify it completely.

Did we mention that this system is fully dependent on pressure? It requires no source of power, such as batteries or electricity. Besides, it doesn’t need any in-built pumps to increase efficiency.

Get the minimum possible loss!

It’s extremely efficient and saves water more than other units of its class! Thanks to its smart water-saving technology that ensures water wastage ratio to 1:1.

All-in-one design! Everything is in one unit!

Brondell circle RO system is designed to fit your kitchen in mind.

It’s one of the smallest reverse osmosis systems available in the market today. With a 13.8 x 9.2 x 16.5 inches footprint, it takes minimum possible space under the sink. 

Its classic beauty would be an understatement. The beautiful design is simply exceptional that we feel it beats other RO systems by far.

The unit keeps the storage tank, tubing, and filters in one housing for protection from physical damage. 

It is the easiest system to install.

You’ll not require any tool to fix it. Brondell filters replacement is also a breeze- simply twist and pull to remove the old filter.

The unit comes with an innovatively designed faucet to increase reach. It is chrome finished, lead-free and NSF certified.

Most importantly, this model is Gold Seal certified for trusted performance.


  • Perfect for a household or a small business 
  • All-in-one, complete and compact system
  • High efficiency, ten times more efficient with water usage
  • Patented technology to eliminate backwash
  • Swift installation and filter replacement 
  • One year manufacturer warranty 


  • The joint of the faucet features cheap plastic that may break after months of use. So, you need to take extra care when using the faucet.

5. Home Master TMHP HydroPerfection Undersink Reverse Osmosis Water Filter System

Home Master TMHP HydroPerfection

Next, we have another excellent undersink RO system from Home Master. This time it’s TMHP HydroPerfection.

If you’re looking for a high-performance RO filtration system for well water with iron, then this is the right choice for you. Of course, this model also works for city water.

You’ll be impressed with its exceptional water purity. 

So, what’s stand out?

Its premium filtration performance purifies water better than most RO systems. You’ll enjoy not only germ-free safe water but also odorless, great-tasting water with added minerals. Thanks to its 9-stage filtration process.

The sediment filter, catalytic carbon filter, and semi-permeable RO membrane work together to flush out 99% of contaminants.

The RO membrane is coated with iron components to protect it from the contaminated well water.

The iron pre-filter is fitted with a catalyst called Redox media KDF85. It helps suck all the dissolved iron from the water. What’s more, this mixed media pre-filter efficiently removes chlorine, pesticides, herbicides, and more.

This model also uses UV light technology as a method of sterilization. It uses UV light instead of chlorine to prevent further contamination, as is the case with chlorine.

It safely sterilizes 99.99% of microorganisms, bacteria, and viruses.

You’ll appreciate its revolutionary modular filter design. Firstly, it speeds up the entire filter replacement process. Secondly, it disrupts the build-up of harmful microorganisms in the system.

There is more…

The non-electric permeate pump enhances the system’s effectiveness. It helps to increase water production by 50% and decreases water wastage by 80%.

Furthermore, the large flow tubes and other high flow components double the water flow rate to the faucet.

Any downside? 

The design isn’t groundbreaking.

For a product with a high price tag, you would expect it to be looking stunning. But TMHP HydroPerfection looks average. No worry! This 9- stage filtration unit’s premium quality and high performance will make you forget its average looks. 


  • Easy to change filters and maintenance 
  • Excellent build quality 
  • Impressive water efficiency 
  • Innovative design 
  • Highly pure, great-tasting water
  • Ideal for well or city water
  • Modular design and faster flow
  • Reduce TDS creep
  • Five years limited warranty 


  • Highly priced. If the price isn’t an issue, we recommend you to buy it. You’ll get back every penny of your investment through its performance.

6. Waterdrop Tankless Reverse Osmosis System, WD-G2-B RO

Waterdrop WD-G2-B RO

If you’re looking for the top-rated tankless RO water filtration system, Waterdrop WD-G2-B is worth consideration.

The innovative tankless design saves over 70% more under-sink storage spaces than does the traditional RO system. It’s only 5.9 inches wide. This small footprint makes it perfect for small offices, cafes, and restaurants.

Reliable water solution!

G2 RO system removes most of the water contaminants, including heavy metals and chemical residues. It flushes out contaminants larger than 0.0001 microns. Thanks to its filter composition technology that helps to achieve a more efficient filtration. 

The composite filter adopts two layers- a sediment PP membrane and an activated carbon block layer. It removes large particles, residual chlorine, and colloids.

The RO membrane, along with activated carbon block, effectively removes over 1000 contaminants, heavy metal, organics, and bacteria. It also improves the taste of water.

Most conveniently, you won’t need to replace the Composite filters in six months as you would do with other RO systems. Of course, replacing the filter is faster and more convenient. The twist-and-pull design lets you replace the filters in 3 seconds.

And you know what else?

Its filter life indicators automatically monitor the filters and notify you of the usage and service life.

This Waterdrop compact unit puts out a cup of filtered water in about 12 s (flow rate of 400 GPD). It always has a stable water flow. Moreover, it saves over 60% of water resulting in a 1:1 drain ratio.

The water and electrical circuit’s integrated design reduces leakage issues, whereas the airtight housing reduces noise.

Excellent lead-free plastic materials and brushed nickel faucet give access to safe drinking water throughout the day.


  • Innovative no-tank design 
  • Excellent filter combination for more effective filtration 
  • No secondary pollution
  • Efficient and quick softened water
  • Stable filtered water supply
  • 30 minutes installation and 3 seconds filter replacement 
  • Low drain rate; saves water


  • It requires under-sink electricity.

7. AmazonBasics AMZN-PB-TLRO4H50T 4-Stage Reverse Osmosis System

AmazonBasics AMZN-PB-TLRO4H50T

If you need a home drinking water system that removes everything from your water, this model from the AmazonBasic brand is a good system.

AmazonBasic 4-stage RO system aims to produce the highest quality drinking water. This professional-grade system provides clean, clear, great-tasting water.

It consists of four separate filters to ensure you’re getting nothing but the best water. Sediment filter, pre-carbon block filter, RO membrane filter, and post-carbon block filter take over the first, second, third, and fourth stages of filtration, respectively.

This unit reduces contaminants, chlorine, particulates, chemicals, unpleasant tastes, and odors from tap water.

You’ll always have enough safe drinking water.

The thin-film membrane is the key to high-level home water purification that quickly fills the tank to meet your daily needs. It can handle up to 50 gallons per day, making it a great choice for any household. Moreover, it comes included with a high capacity storage tank, so you’ll never run out of pure water.

This model is certified to ECE and ANSI standards 58 & 372. It ensures you the power to reduce the levels of contaminants in your water, including lead, fluoride, arsenic, TDS, turbidity, and more.

This effective filtration system is rigorously tested for safety. Other than the lead-free faucet, all NSF certified components ensure safe filtration for you and your family.

Forget the guesswork!

The included Electronic Monitor Faucet lets you know when it is time to change your filters. Of course, the faucet is stylish in appearance and well made.

No-mess Replacement filter changes!

The installation of this unit is an easy process. It easily connects to existing plumbing with “twist-lock” manifolds. With your purchase, you’ll get a detailed instruction manual and installation video.


  • High-performance
  • High production rate
  • Reduce levels of fluoride, lead, and more
  • Easy to change filters
  • Easy maintenance
  • Eco-friendly
  • Easy DIY installation


  • It doesn’t remineralize water for drinking.

8. Aquasana OptimH20 RO System

Aquasana OptimH2O Water Filter System

Aquasana OptimH2O will instantly transform ordinary tap water into clean, extraordinary water.

Best-in-class filtering technology!

It’s the first filter system that combines advanced Claryum filtration, powerful reverse osmosis, and remineralization technology.

It’s tested and proven to provide you with optimally healthy, clean water.

Aquasana OptimH2O is the first and only filter with P473 (PFOA and PFOS) certification. It’s also tested and certified to NSF/ ANSI standards 42, 53, 58, and 401.

It removes 5X more contaminants than other RO systems. But worry not; it maintains the benefits of healthy minerals that other RO systems simply remove.

It’s worth noting that this system flushes out 99% of 86 contaminants, plus 97% of chlorine and 95% of fluoride from tap water.

The CTO carbon reduces chlorine taste and odor, protecting the RO membrane from damage.

Next, water is forced through a semipermeable membrane to remove fluoride, nitrate, arsenic, and TDS.

The Claryum carbon filter is engineered to remove more contaminants than RO alone.

Finally, the filtered water is remineralized to add back healthy amounts of potassium, magnesium, and calcium, giving you alkaline, pH balanced water.

The result is great-tasting, safe water that provides optimum hydration for you and your beloved family. Notably, it can filter out 0.5 gallons every minute and 35 gallons per day for instant access to healthy water.

Replacing your filters is a snap!

Installation of the unit and replacement of the filters are super easy. You don’t need to disconnect water lines and hoses.  Simply twist off the carbon and Claryum filter housing and fix the new one. All parts for installation are included.

And what else?

OptimH2O comes equipped with a stylish all-metal designer faucet. Conveniently, the faucet is available in a variety of finishes to match your kitchen décor. It’s 100% lead-free, ensuring safety.


  • Advanced filtering technology
  • Keep the healthy minerals.
  • Easy DIY installation and filter replacements
  • NSF full-system certification
  • Low maintenance
  • 2-Year Limited Warranty


  • Several users have complained that it slightly reduces the water flow.

9. Express Water Reverse Osmosis ROALKUV10M UV Water Filtration System

Express Water ROALKUV10M UV

Express Water UV is an incredibly efficient and high scoring RO water filtration system and a complete solution for your drinking water.

 The unit does not look particularly unique or special. But several unique features set this system apart from the rest of the crowd.

First of all, this 11- stage filtration system removes up to 99% of contaminants. And it works for the city and well water.

The first, second, and third stage filtrations flush out different pollutants and particles from water. These early stages also extend the life of the RO membrane (fourth stage).

The RO membrane removes the most difficult contaminants, such as arsenic, lead, fluoride, TDS, and more.

The 5th to 9th stages adds five stages of antioxidants, mineralization, and oxygen to your water.

Your drinking water is always free from microbes!

Powerful UV-C disinfects (stage 10) also removes E.coli, cysts, coliform, bacteria, and microorganisms.

The post activated carbon filter at stage 11 removes any possible odor and taste.

Express water 11 stage system mineralizes filtered water the way as the natural springs on Earth.

It adds ionically activated minerals to water as it passes through five types of mineral rocks. 

What’s great about it?

This efficient filtration and the quick delivery system produces 100 gallons of pure water a day.

The double-sealed filter housing preserves your filters and your kitchen. What’s more, it ensures the best filtration efficiency and value.

The emergency Leak Stop Valve shuts off water flow if it detects excess water or moisture. Conveniently, there is a fabric disk in contact with the floor beside the system. If, for any reason, water is absorbed, the flow to the system will stop automatically.

You don’t need to waste money on professional installation!

Firstly, this compact system fits perfectly under the counter in a cabinet, basement, or other remote locations, making it perfect for apartments, houses, RV, and office uses.

Secondly, its quick, easy-to-understand design and labeled color matched system lets you install it yourself. The Quick Connect Adapter and Brass Feed Adapter come included, so you don’t need to go to the hardware store to buy parts. Moreover, the included adapter fits the two common sizes of under sink pipes- -3/8″ and 1/2″.

Filter replacement is also quick and easy with clear labels and simple design. The quick-connect system is easy, fast, and helps prevent leaks. It’s worth noting that the sediment, carbon block, activated carbon filter need to be replaced only twice a year. On the other hand, you may require to replace the RO membrane, Post Carbon, and Alkaline only once a year.

Quality Guaranteed! The 1-year warranty on these models helps you to buy it confidently.


  • Up to 99% removal rate
  • Filter over 108 major contaminants
  • Powerful UV protection for water
  • Added essential minerals
  • Efficient filtration & fast flow rate
  • Automatic water leak detection
  • Certified by an independent laboratory to NSF standard 58
  • Pretty straightforward to install
  • 1-year manufacturer warranty


  • No issues found


Best Under Sink Reverse Osmosis System

That’s it!

Live healthier with the ultra-safe, pure drinking water filtered by any of these 9 best under sink reverse osmosis system.

No matter which one you pick from our top-list, it’ll dramatically improve the taste, color, and odor of your water.

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