Reverse Osmosis Filters

DRINKING WATER FILTERS

Reverse Osmosis
Filter Reviews

While there are several types of systems to choose from, reverse osmosis water filters are one of the most popular options because of their high performance. These systems can remove up to 99% of contaminants in tap water, and many experts consider reverse osmosis to be the most powerful and effective water filtration method available for home use.

What is a Reverse Osmosis System?

Reverse osmosis (RO) is a water filtration method that removes contaminants by pushing highly pressurized water through a semipermeable membrane. As water passes through the membrane, contaminants are left behind so that only clean, filtered water remains. 

Reverse osmosis systems use this method to filter tap water in a home. The method is effective at reducing up to 99% of contaminants in water, and it’s the only method proven to effectively remove fluoride. In fact, reverse osmosis is often considered the most effective filtration method overall.

How Does a Reverse Osmosis System Work?

Reverse osmosis water filters work by forcing pressurized water through a semipermeable membrane that separates the contaminants from the water. By forcing pressurized water through the membrane, contaminants are left behind and only clean water can pass through.

While reverse osmosis is highly effective on its own, most systems use a series of filtration steps to offer better performance. For more information, we’ve provided a breakdown of all the stages RO filters typically use to improve the quality of tap water. However, it should be noted that not all reverse osmosis water filters will utilize all four of these stages, some may not feature a sediment filter or remineralize the water after the filtration process. When choosing a reverse osmosis water filter, make sure it features all the stages you find important:

Sediment Pre-Filter

The first stage is the removal of sediment particles through a screen-mesh pre-filter. Dust, dirt, rust, sodium, and any larger particles are caught in the mesh and blocked from moving further through the process.

Activated Carbon Filter

The second stage is the activated carbon filter. Activated carbon is created from high carbon materials like wood, coal, or coconut shells. These materials are heated to produce a char, which is treated to create a porous material that’s ideal for water filtration. The porous nature of activated carbon allows it to act like a sponge, attracting and trapping contaminants as water passes through. Activated carbon filters are commonly used in almost every type of water filtration system, including reverse osmosis systems that feature multi-stage filtration.

Semipermeable Membrane

The key to reverse osmosis systems is the semipermeable membrane, which splits the water and contaminants by forcing water through the membrane under intense pressure to remove dissolved solids, fluoride, nitrates, and salts among other solutes. In fact, this stage is so effective at removing impurities, that it often strips water of healthy minerals as well.

Remineralization

Water that has been filtered through reverse osmosis may lack minerals because the filtration method removes more than it needs to. The lack of minerals in RO water can affect the health benefits and taste (RO water is often said to have a “flat” taste), so some systems address this through the use of an additional remineralization stage. The remineralization stage adds a concentration of the lost minerals back to improve the taste and health benefits of the water. It’s important to note that not all reverse osmosis systems feature remineralization technology, so check for this feature if these factors are important to you.

Filter and reverse osmosis tank of a water filtration system.

Buyer’s Guide for Reverse Osmosis Systems

It’s easy to get confused by the terminology used to describe reverse osmosis water systems. So we’ve created this buyer’s guide that includes helpful information on what an RO system is, how the technology works, when you need one of these systems, and how to choose an RO filter.

Reverse Osmosis Filters

product

Aquasana - SmartFlow™ Reverse Osmosis - AQ-SFRO

High-efficiency reverse osmosis system removes up to 99.99% of 90 contaminants, including fluoride, arsenic, chlorine, and lead.

Learn More about the Aquasana - AQ-SFRO
Best Price*

System

$199.99

Replacement Cost

$169.97 - 4 filters

Performance

Total Contaminants Reduced

90

Certified

NSF/ANSI 42, 53, 58, 401, and CSA B483.1

Remineralizer Stage

Yes

Faucet Finish Option

Yes

Best Price*

System

$199.99

Replacement

$169.97 - 4 filters

Performance

Total Contaminants Reduced

90

Certified

NSF/ANSI 42, 53, 58, 401, and CSA B483.1

Remineralizer Stage

Yes

Faucet Finish Option

Yes

Key Contaminants Removed:
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Fluoride

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Lead

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Chlorine/Chloramines

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PFOA/PFOS

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Pesticides & Herbicides

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VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 90-day satisfaction guarantee
  • 2-year warranty
  • Replacement subscription option
product

A. O. Smith - High-Efficiency Reverse Osmosis - AOS-HERO

Maximum filtration - reverse osmosis reduces up to 99% of 90 harmful contaminants including bacteria, viruses, lead, fluoride, chromium, mercury, asbestos, pesticides, pharmaceuticals, and chlorine

Learn More about the A. O. Smith - AOS-HERO
Best Price*

System

$249.99

Replacement Cost

$174.96/3 filters

Performance

Total Contaminants Reduced

90

Certified

NSF/ANSI 42, 53, 58, 401

Remineralizer Stage

No

Faucet Finish Option

No

Best Price*

System

$249.99

Replacement

$174.96/3 filters

Performance

Total Contaminants Reduced

90

Certified

NSF/ANSI 42, 53, 58, 401

Remineralizer Stage

No

Faucet Finish Option

No

Key Contaminants Removed:
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Fluoride

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Lead

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Chlorine/Chloramines

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PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 90-day satisfaction guarantee
  • 2-year warranty
product

iSpring - 6-Stage Reverse Osmosis System - RCC7AK

Converts your water by reducing chlorine, fluoride, lead, arsenic, asbestos, calcium, sodium and more. Designed to restore the natural alkalinity and mineral balance of water.

Learn More about the iSpring - RCC7AK
Best Price*

System

$209.98

Replacement Cost

$77.00

Performance

Total Contaminants Reduced

13

Certified

NSF/ANSI 58

Remineralizer Stage

Yes

Faucet Finish Option

No

Best Price*

System

$209.98

Replacement

$77.00

Performance

Total Contaminants Reduced

13

Certified

NSF/ANSI 58

Remineralizer Stage

Yes

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 30-day satisfaction gurantee
  • 1-year warranty
product

Bluevua - Countertop Reverse Osmosis Filtration System - 100ROPOT

A countertop reverse osmosis water filter system, offering the ultimate level of filtration. Remove 99.99% of contaminants using a premium 4-level system. Enjoy tasty water free from chlorides, lead, chlorine, fluoride, heavy metals, mercury, chloramine, chromium, arsenic, and radium. This state-of-the-art system will leave you with the purest and tastiest water every time.

Learn More about the Bluevua - 100ROPOT
Best Price*

System

$389.00

Replacement Cost

$149.96/4 filters

Performance

Total Contaminants Reduced

6

Certified

NSF/ANSI 58

Remineralizer Stage

Yes

Faucet Finish Option

No

Best Price*

System

$389.00

Replacement

$149.96/4 filters

Performance

Total Contaminants Reduced

6

Certified

NSF/ANSI 58

Remineralizer Stage

Yes

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 30-day satisfaction guarantee
  • 1-year warranty
  • Smart technology
product

Whirlpool - UltraEase Reverse Osmosis Filtration System - WHER25

Creates quality water for drinking, cooking, coffee, and ice. Reduces or removes many contaminants including lead, cysts, dissolved solids, chlorine taste and odor, sediment, arsenic

Learn More about the Whirlpool - WHER25
Best Price*

System

$230.14

Replacement Cost

$143.00

Performance

Total Contaminants Reduced

26

Certified

NSF 58, 42

Remineralizer Stage

No

Faucet Finish Option

No

Best Price*

System

$230.14

Replacement

$143.00

Performance

Total Contaminants Reduced

26

Certified

NSF 58, 42

Remineralizer Stage

No

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 1-year warranty
product

APEC - 5-Stage Reverse Osmosis Drinking Water Filter - ROES-50

Delivers filtered water at an affordable price. Tested and certified to remove up to 99% of contaminants including chlorine, VOCs, flouride, lead and more.

Learn More about the APEC - ROES-50
Best Price*

System

$199.95

Replacement Cost

$96.00

Performance

Total Contaminants Reduced

52

Certified

NSF 58

Remineralizer Stage

No

Faucet Finish Option

No

Best Price*

System

$199.95

Replacement

$96.00

Performance

Total Contaminants Reduced

52

Certified

NSF 58

Remineralizer Stage

No

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 1-year warranty
  • 2-year warranty
product

Frizzlife - Tankless Reverse Osmosis Water System - PD600-TAM3

The water from RO membrane is slightly acidic, which also removes natural mineral. The 3rd stage of filter solves both issues of conventional RO systems! It balances the alkalinity of RO water and adjusts the PH to more than 7.5. Drinking weakly alkaline water is beneficial to your health. It also restores health-benefiting essential minerals to your water. Frizzlife PD600 produces healthiest and greatest tasting water for you.

Learn More about the Frizzlife - PD600-TAM3
Best Price*

System

$469.99

Replacement Cost

$149.97/3 filters

Performance

Total Contaminants Reduced

8

Remineralizer Stage

Yes

Faucet Finish Option

No

Best Price*

System

$469.99

Replacement

$149.97/3 filters

Performance

Total Contaminants Reduced

8

Remineralizer Stage

Yes

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 1-year warranty
  • Smart technology
  • Space Saving
product

Waterdrop - G2P600 Reverse Osmosis Water Filtration System for Home - WD-G2P600-W

Uses acomposite filter technology and 7-stage filtration to reduce most contaminants. Can produce up to 600 gallons of filtered water per day.

Learn More about the Waterdrop - WD-G2P600-W
Best Price*

System

$287.00

Replacement Cost

$130.00

Performance

Total Contaminants Reduced

-

Remineralizer Stage

Yes

Faucet Finish Option

No

Best Price*

System

$287.00

Replacement

$130.00

Performance

Total Contaminants Reduced

-

Remineralizer Stage

Yes

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • 30-day satisfaction guarantee
  • 1-year warranty
  • Smart technology
  • Space Saving
product

SimPure - Countertop Reverse Osmosis Water Filter Dispenser - Y7P-BW

4-Stage Countertop RO Reverse Osmosis & UV Water Filtration System

Learn More about the SimPure - Y7P-BW
Best Price*

System

$289.99

Replacement Cost

$58.00/2 filters

Performance

Total Contaminants Reduced

17

Certified

NSF/ANSI 58

Remineralizer Stage

No

Faucet Finish Option

No

Best Price*

System

$289.99

Replacement

$58.00/2 filters

Performance

Total Contaminants Reduced

17

Certified

NSF/ANSI 58

Remineralizer Stage

No

Faucet Finish Option

No

Key Contaminants Removed:
icons

Fluoride

icons

Lead

icons

Chlorine/Chloramines

icons

PFOA/PFOS

icons

Pesticides & Herbicides

icons

VOCs

icons

Pharmaceuticals

icons

Cysts

icons

Microplastics

Other Benefits:
  • Smart technology

When Do You Need a Reverse Osmosis System?

Reverse osmosis water systems are considered the most effective at removing contaminants from water, so if your area has a lot of lead, mercury, fluoride, or chlorine — a reverse osmosis water filter is an excellent choice for your home. The aforementioned contaminants, which we’ll detail further below, range in seriousness from being deadly neurotoxins to spoiling the balance and taste of your family’s drinking water. Briefly touching on lead specifically — if you are someone with an older home or live in an area where lead pipes are prevalent, a reverse osmosis system is an excellent choice because it’s a point of use filter that cleans water right before you use it, meaning you don’t have to worry about contamination from the pipes in your home.

How to Choose the Best Reverse Osmosis System for your Home

When selecting the best reverse osmosis filtration system, there are many factors to consider. It’s always best practice to take stock of the number of stages the filter has. Regarding one stage, in particular, any filter that’s adequate should have a remineralization stage for pH-balanced and incredible tasting water. If your area is prone to a wide range of contaminants, a reverse osmosis filtration system can be a great solution. Conversely, if your area is typically prone to a specific set of contaminants, a filter with fewer stages might be sufficient for your needs.

Here are some other things to consider when choosing the best reverse osmosis system for your home:

Filter Size and Capacity

Buyers will want to ensure that they match the filter to the size of their home and their estimated water usage. Regarding the physical size of the filter, you’ll want to consider the space you have available below the sink you plan to install it under and check the dimensions of any filter you’re looking at to ensure there’s sufficient space.

The size of the filter may also relate to it’s capacity, which indicates how much water it can filter before it needs to be replaced. In most cases, the filter capacity you select should correlate with the size of your home and number of residents. 

If you purchase an RO system with a low capacity for a crowded home, you’ll wear down the filter causing it to lose efficiency quicker than what is expected for normal use. On the other hand, purchasing an RO system with a high capacity for a small home may be an unnecessary expense. 

Contaminants

When considering which filter to buy, the most important factor is what contaminants the filter is proven to remove. Because of the Safe Drinking Water Act (SDWA) consumers are entitled to request a local water quality report which details the contaminants present in their local water. Although what specific contaminants each RO system removes can vary, here are a few commonly removed contaminants along with assorted facts associated with each:

  • Fluoride – Reverse osmosis is the only water filtration method proven to effectively remove fluoride. Excessive fluoride has been linked to high blood pressure, neurological issues, seizures, and more.
  • Mercury – Mercury is a potent neurotoxin that can affect the human nervous system.
  • Lead – Lead can enter drinking water when plumbing materials that contain lead corrode, especially where the water has high acidity or low mineral content that corrodes pipes and fixtures. Exposure to high levels of lead may cause anemia, weakness, and kidney and brain damage.
  • Asbestos – Asbestos cement (AC) pipes were mainly used before the 1980s and could still be present in your home. After 30+ years of use, wear, and corrosion, the safety of unmaintained infrastructure like this can pose health threats including cancer.

Certifications

Properly informed buyers will want to ensure their systems are certified by third-party organizations such as NSF International, The International Association of Plumbing and Mechanical Officials (IAPMO) or the Water Quality Assocition (WQA). These organizations offer professional certifications that ensure these water filtration systems remove or reduce contaminants to the levels they claim to. You should purchase a reverse osmosis or other water filtration system that has received a third-party certification.

Cost

Reverse osmosis water systems typically range from a few hundred dollars upwards to thousands of dollars, which can be far more expensive than alternatives like pitcher and dispenser filters.

The most expensive RO option, a whole house reverse osmosis system, is somewhat rare and on average will cost thousands of dollars. Whole house RO systems are known as point-of-entry systems, as they treat the main water line of a home. The reverse osmosis water systems of the under sink variety are known as point-of-use systems as they interact with the house’s water at the point of water consumption. These systems on average cost a few hundred dollars. Self-containing countertop reverse osmosis systems are typically a few hundred dollars, too, but the additional cost of professional installation isn’t needed. When budgeting, a buyer should also account for annual maintenance including filter replacements and potential add-ons.

Reverse Osmosis System Installation

Depending on the form factor of your reverse osmosis water system (whole house, under sink, or countertop) a buyer might consider professional installation. Countertop systems don’t require a hookup or plumbing, as they are fully self-contained and can usually be installed by the homeowner without difficulty. The whole house and under sink filtration systems will, of course, be more complicated. Often, manufacturers will recommend hiring a plumber to perform the installation. If you’re unsure about the installation process and if you’d need a professional, see if you can find a manual or installation video from the manufacturer to get a better idea of what the process looks like.

Reverse Osmosis System Maintenance

Be sure to follow the instructions, including the recommended filter replacement schedule, denoted in the manufacturer’s instruction manual. If the system contains multiple stages of filtration, each filter may need to be replaced at different intervals. Some retailers may have programs in place to automatically remind or send you a replacement when it’s time for a filter swap, so check if this option is available to give you one less thing to track. 

For homeowners with hard water, RO filters will need to be replaced at a more frequent rate, unless you utilize a water softener or conditioner. For reference, the southwest is regularly associated with having the hardest water in the U.S. Be sure to do your research on your water’s hardness and consult the manufacturer’s manual from there.

Filling glass of water from sink.

Final Considerations

From here you should have everything at your fingertips to make the correct purchasing decision for your home’s reverse osmosis water filtration system needs. Water filtration is paramount for your family’s health, so be sure to consider all the information we’ve provided in order to choose the best option. For more information, check out the reviews of each product in the section at the top to see how systems compare.

Frequently Asked Questions

Other Types of Drinking Water Filters

Little boy drinking glass of water at home.

Direct Connect

Direct Connect water filters – also known as Main Faucet Filters – are gaining popularity because of their high performance and easy installation. We’ll help you make the best choice for your home.

Under Sink

Under Sink water filters offer a great mix of performance, affordability, easy installation, and simple maintenance. Learn about the benefits of these systems, the types available, and top selections.

Woman washing fruit using faucet attachment water filter.

Faucet Attach

Faucet Attach water filters are a popular choice due to their compact form, easy installation, and entry-level price point relative to other options. Learn more about these filters.

Washing salad using filtered water from dedicated faucet.

Pitchers & Dispensers

Water filter pitchers and dispensers are popular options because of their low cost, ease of use, portability, and lack of required installation. But not all options are equally good.

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*Product performance claims and prices were taken from publicly available information on Amazon, are accurate as of 1/3/2024, and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply to the purchase of this product. Cost per gallon is calculated as replacement filter price/capacity. Not all contaminants will be listed in charts. If you find information that is inaccurate, please send the correct info with supporting documentation to info@waterfiltercomparisons.com, and we will address any errors. As an Amazon Associate, Water Filter Comparisons receives a commission on purchases made through our Amazon links.