clock menu more-arrow no yes mobile

The 5 Best Reverse Osmosis Systems (2022 Review)

A reverse osmosis system gives you clean water without relying on tap or bottled water. In this review, the This Old House Reviews Team researched the five best reverse osmosis systems on Amazon to help you find the product that’s right for you and your home. The products included in this article are available at various home improvement stores, local home centers, and online retailers like Amazon.

Reverse Osmosis System Courtesy AquaTru

Reverse osmosis systems give you cleaner water by removing dirt, chemicals, microorganisms, and other contaminants. The This Old House Reviews Team has found the best reverse osmosis systems on Amazon to fit your sink. These are our top picks.

Top 5 Reverse Osmosis Systems

Best American-Made System: APEC Water Systems Five-Stage Reverse Osmosis System

This reverse osmosis system was designed, engineered, and assembled in the United States to ensure a high-quality product. It uses a five-stage filtration system to remove contaminants from any type of water, including mineral-rich well water and standard tap water.

Key Features

  • 25 pounds
  • Four-gallon capacity
  • Under-sink installation
  • One-year warranty with a two-year warranty available upon registration

What Customers Are Saying

Reviews complimented the efficiency of this system, which multiple customers said saved them more energy and money than previous reverse osmosis systems they had used. However, some customers weren’t satisfied with the system’s installation process, which required a cordless drill to drill holes.

Best Water Taste: iSpring Six-Stage Under-Sink Reverse Osmosis System

This reverse osmosis system removes up to 99% of asbestos, fluoride, and other harmful chemicals. After removing over 1,000 contaminants, this six-stage reverse osmosis system remineralizes your water. This makes it a dual-function system that improves both your health and your water’s taste.

Key Features

  • 20 pounds
  • 75-gallon capacity
  • Under-sink installation
  • One-year warranty

What Customers Are Saying

Customers frequently complimented how easy to install this system was, with the process being easy enough for even those with no DIY experience to manage. Reviewers who rated this product poorly complained that the system’s parts leaked.

Best Leak Detection: Express Water Reverse Osmosis Five-Stage System

This five-stage reverse osmosis system includes filters that remove pesticides, chlorine, and microorganisms. It also has a leak detector that stops water flow if moisture is found. The filters are also double-sealed to further protect against leaks.

Key Features

  • 11.8 pounds
  • Four-gallon capacity
  • Under-sink installation
  • One-year warranty

What Customers Are Saying

Customers praised the system’s filter design because the swivel connections allowed for quick filter changes without removing any tubing. However, dissatisfied customers complained about the system’s maintenance process, which required regular intensive cleaning in addition to filter changes.

Best Tankless System: Waterdrop Reverse Osmosis Filtration System

Save space under your sink with this tankless reverse osmosis system that features a seven-layer membrane with cotton and activated carbon components. This tankless system might be especially beneficial for those who have allergies, as its design prevents secondary pollen transfer that’s seen with some other reverse osmosis systems.

Key Features

  • 31 pounds
  • 400-gallon capacity
  • Under-sink installation
  • One-year warranty

What Customers Are Saying

Customers praised this system’s effectiveness. Several customers purchased tap water testing kits to determine the efficiency of this system and found that the water it provided was comparable to filtered bottled water. However, some customers found its faucet to be flimsy.

Best Countertop System: AquaTru Countertop Water Filtration Four-Stage System

Purify water on your countertop and cut down on installation time with this small reverse osmosis system that includes a removable tank, a four-stage filter, and a dispenser button. This model’s sleek design also blends seamlessly with any kitchen.

Key Features

  • 22.84 pounds
  • Three-quart capacity
  • Countertop installation
  • One-year warranty

What Customers Are Saying

Customers said that this reverse osmosis system was strong enough to remove even solid particles from the gallons of water it filtered. However, customers who weren’t satisfied with their purchase complained that it stopped working after a short period of time.

Buyer’s Guide

A reverse osmosis system removes contaminants from your tap water by passing it through a series of filters. This buying guide will help you pick the best reverse osmosis system for your sink.


Reverse osmosis systems can vary greatly in size. Most models are designed to be stored underneath a sink, although countertop versions also exist. Measure how much space you have under or around your sink before purchasing a reverse osmosis system.


Some reverse osmosis systems have a tank that stores water before it’s transferred to your sink. Others forgo the tank to save space. The type you purchase should depend on how much space you have in your kitchen.

Filter Type

Reverse osmosis systems move water through three to six filters to remove contaminants. Common types of filters include:

  • Sediment: This type of filter removes dirt and other large particles.
  • Carbon: This type removes chlorine.
  • Reverse osmosis: These filters remove particles that are larger than water molecules.
  • UV: This type of filter kills microorganisms.
  • Targeted: These filters remove specific types of contaminants, such as nitrate or fluoride. They’re only needed if these contaminants are present in large quantities.
  • Remineralization: This filter introduces calcium and magnesium into the purified water to balance its pH.


The amount of water that a reverse osmosis system can purify at one time is typically measured in gallons. Choose a capacity based on how much water you and your family use in a day. For example, if you live alone, a system that purifies four gallons of water will be enough. However, if you have a family of five, you will need a reverse osmosis system that can purify at least 20 gallons of water.

Safety Features

Some reverse osmosis systems have built-in features to ensure that they run smoothly. Common features include leak detectors and filter replacement indicators.

Frequently Asked Questions

How does a reverse osmosis system work?

A reverse osmosis system removes dirt, bacteria, and chemicals from your drinking water. It does this by passing water through a series of filters that each target a specific contaminant. Since the filters are semipermeable membranes, they allow water to pass through them while trapping undesirable molecules. The resulting water is purer than standard tap water.

Why do I need a reverse osmosis system?

A reverse osmosis system can provide any household with healthier and better-tasting water. However, it’s especially important to use a reverse osmosis system if you live in an area with poor water quality.

How often do I need to replace the filters in my reverse osmosis system?

Replace the filters in your reverse osmosis system at least once per year. If a filter gets clogged or damaged, replace it sooner. Some reverse osmosis systems have warning systems that tell you when a filter is failing or nearing the end of its life.

Why Trust The This Old House Reviews Team

This Old House has empowered homeowners for more than four decades with top-notch home improvement content in the form of television programs, print media, and digital content on its website and social media platforms. The This Old House Reviews Team focuses on creating in-depth product and service review content to help inform your purchasing decision for just about any item or resource that you might need for your home. The This Old House Reviews Team has written over 1,000 reviews on products in the home space, from cordless drills to kitchen trash cans, lawn mowers, and dining room decorations.

We recommend products in each review using an intensive research process, spending hours combing through the best available models on Amazon. For a product to make our list of top picks, it must hold a solid sales record on Amazon, have consistently positive customer reviews, and offer unique features, among other factors. After narrowing down our list of recommendations, we conduct additional research and sometimes in-person testing to ensure that the products meet our standards. Once we conclude the research phase, we craft a well-rounded, user-friendly article that includes our recommended products and additional information to help homeowners like you make the right purchase.

To share feedback or ask a question about this article, send a note to our Reviews Team at