Best Reverse Osmosis System

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Best Reverse Osmosis System

Buying the best reverse osmosis system for your kitchen guarantees pure, ready-to-drink water for up to a year. RO systems are a go-to option for any home, whether big or small, thanks to their relatively affordable prices. Most importantly, these systems purify water in up to seven stages to guarantee 99.99% contaminants removal. They also improve natural taste and odor to promote healthy drinking habits. 

We tested seven reverse osmosis systems and found iSpring RCC7AK 6-Stage Under-Sink Reverse Osmosis Drinking Water Filter System to be the best product overall, thanks to the small micron rating of 0.0001. You’re looking at a system that guarantees total value for every buck you spend on it. 

We leverage direct expert recommendations and reviews to highlight RO systems with the best qualities. Our hardworking technicians spent at least 20 hours testing a product’s efficiency and reliability. We also check systems with the highest positive customer reviews on reputable online-vending websites such as Amazon. 

Our top-ranking product is ideal if you want the best reverse osmosis system in the market. You can opt for the best runner-up product if you’re after an efficient, budget-friendly system. Other products on our review list include the best countertop, the best quality, the best money value, the best for icemakers, and the best longevity.

Best Reverse Osmosis Systems

  1. iSpring RCC7AK 6-Stage Under-Sink Reverse Osmosis Drinking Water Filter System– Best Overall
  2. Home Master TMAFC- ERP Artesian Full Contact Under-Sink Reverse Osmosis Water Filter System– Best Runner-Up
  3. RKIN OnliPure Countertop Reverse Osmosis Water Filter System– Best Countertop
  4. Waterdrop RO Reverse Osmosis Water Filtration System– Best Quality
  5. Express Water RO5DX Reverse Osmosis Filtration– Best Money Value
  6. AquaTru Countertop Water Filtration Purification System– Best Longevity

Best Reverse Osmosis System Reviews

1. iSpring RCC7AK 6-Stage Under-Sink Reverse Osmosis Drinking Water Filter System

iSpring RCC7AK 6-Stage Under-Sink Reverse Osmosis Drinking Water Filter System is the best product overall, thanks to its high filtration performance. It comes with a reinforced, transparent housing at the first purification stage.

This gives you a quick way of inspecting the filter’s condition and the contaminants removed. Thus, you eliminate guesswork when replacement time is around the corner.

iSpring RCC7AK Water Filter Review

This reverse osmosis system features multiple water filters, including an outer layer of 5.0-micron rating and an inner layer of 0.0001-micron rating.

Unlike traditional RO systems, this product has a sixth, additional filtration stage to ensure a balanced water pH. Balanced alkalinity gives your water a natural taste and odor.

You’re looking at a European-style faucet that brings an aesthetic appeal to your kitchen. The white finishing is neutral and blends with any interior décor. Moreover, the manufacturer offers a money-back guarantee for all its RO systems. This after-sale service gives you a 100% customer satisfaction guarantee.

You’ll have this RO system up and running in less than thirty minutes since its design is a DIY installation. The packaging comes with well-organized instructions, including links to videos. You can also contact the technical support team for leak-free installation.


  • Warranty – Limited warranty
  • Filtration Type – Reverse osmosis, alkaline
  • Filter Life (Till replacement) – six months
  • Filter Stages – Six
  • Capacity – 5 gallon water reservoir
  • Certifications – Certified to NSF/ANSI 58
  • Micron Rating – 0.0001


  • Alkaline mineralization-layered filtration
  • Filters over 99% of more than 1000 contaminants
  • Pure water (a pH of 8.0 and above )


  • Higher wastewater to filter water ratio
  • It is relatively pricey

2. Home Master TMAFC- ERP Artesian Full Contact Under-Sink Reverse Osmosis Water Filter System

Home Master TMAFC- ERP Artesian Full Contact Under-Sink Reverse Osmosis Water Filter System is the best runner-up product, thanks to its ultra-filtration technology.

The granular carbon filtration media guarantees more contact time without pressure to ensure faster flow rates throughout. Thus, you’re looking at a reverse osmosis system that will serve a big household during on-demand applications.

Home Master TMAFC-ERP Water Filter Review

Changing the filters is relatively easy to save you time and frustration. You’ll need to replace the filtration media after a year or 2,000 gallons, whichever comes first.

Forget about filter systems that require plumbing tools and brute force to extract sealed cartridges (blockage from accumulated contaminants and mineral sediments). This system has a modular design that gives full access and visibility for a quick, effortless filter replacement.

This reverse osmosis system is ideal for multiple applications, including city water and private well water conditions filtration. It uses seven purification stages to filter and remove up to 99% of chlorine and thousands of other contaminants. However, this system works efficiently in feed water pressure of about 40 psi to 90 psi and temperatures of 40°F and 100°F.

You’ll likely experience a 100% customer satisfaction guarantee with this reverse osmosis system. It exceeds the NSF standards and certifications for material safety and high purification performance. Moreover, the manufacturer offers a 5-year limited warranty on defects emanating from the production line.


  • Warranty – 5 year limited warranty
  • Filtration Type – Activated carbon, reverse osmosis
  • Filter Life (Till replacement) – One year
  • Filter Stages – 7
  • Capacity – 2,000 gallons
  • Certifications – Certified frustration-free
  • Micron Rating – 0.0001


  • 0.0001-micron rating
  • 2x coconut shell activated carbon
  • Dedicated sediment filter


  • Under-sink applications only
  • Relatively expensive price tag

3. RKIN OnliPure Countertop Reverse Osmosis Water Filter System

RKIN OnliPure Countertop Reverse Osmosis Water Filter System is a go-to option for homeowners who want an easy-to-use product with hassle-free maintenance. This water filter system doesn’t require any installation process; placing it on a flat surface suffices.

You only need to fill the bottom pitcher for water to flow on the top container in about 15 minutes. The unit turns itself off after passing 0.5 gallons of purified water to the top container.

OnliPure Water Filter Review

This osmosis water filter system is a go-to option if you want to drink relatively alkaline water with a pH of 8.0. Alkaline water is beneficial for optimum homeostatic processes. Moreover, the filtration media replaces the minerals lost in the purification stages.

These minerals include calcium and magnesium for healthy bones and teeth. You get to enjoy the same health, taste, and flavor properties that your favorite bottled water gives you.

The manufacturer notes this reverse osmosis system will give you lower ppm levels of Total Dissolved Solids (TDS). Our technicians tested a glass of pure water from this machine’s faucet, and it confirmed consistent results. Your tap water probably has TDS if the piping system passes through agricultural and urban water runoff or clay-rich mountain waters. Residents around a point of pollution discharge from sewage plants may also experience the same.

The hardware design is stylish, featuring two color options to match your interior décor. Trust this water filter to add an aesthetic appeal to your office desk or kitchen. You don’t need to disrupt your kitchen arrangement as this product is space-efficient. Place it in the tiniest place anyone can imagine without additional top or side-clearance.


  • Warranty – Limited warranty
  • Filtration Type – Reverse osmosis
  • Filter Life (Till replacement) – 12 months
  • Filter Stages – Four
  • Capacity – 75 gallons per day
  • Certifications – NSF/ANSI certified
  • Micron Rating – 5.0


  • Two-color options for a variety
  • High capacity RO water filter
  • It gives alkaline water


  • Not everyone likes alkaline water
  • Countertop application only

4. Waterdrop RO Reverse Osmosis Water Filtration System

Waterdrop RO Reverse Osmosis Water Filtration System makes the best quality product on this review list, thanks to its new composite filter element technology.

This system filters your water without using a storage tank. Thus, you get to enjoy healthy water, free of secondary pollution, prevalent in storage tanks. Besides, the tankless design helps you maximize space in your kitchen.

Waterdrop Reverse Osmosis Review

You’re looking at the first-ever RO filtration system with composite filters that remove impurities from your tap water in seven stages. A single pre-sediment filter equals up to three purification stages to trap tiny and large contaminants.

The coconut shell filter features activated carbon granules to increase the contact time and surface area for purification.

This RO water filtration system is a go-to product for big households of about five people. The filter purifies a glass of water in about 12 seconds to save you time. It can also remove contaminants from up to 400 gallons of water per day; hence ideal for on-demand applications. It will meet the needs of a mid-sized company with up to 10 employees.

Unlike traditional RO systems, this model has a 1:1 low drain ratio that helps you save water waste by up to 300%. Thus, you get to enjoy a filtration system that works efficiently while keeping your water bills low. However, it takes quite a while to have this system up and running. You’ll need to flush it for up to 30 minutes until you see a blue light on the faucet.


  • Warranty – Limited warranty
  • Filtration Type – Reverse osmosis
  • Filter Life (Till replacement) – Six months
  • Filter Stages – Seven
  • Capacity – Up to 400 gallons per day (tankless)
  • Certifications – NSF/ANSI 58 and 372 certified
  • Micron Rating – 0.01


  • Seven filtration stages
  • Efficient, tankless design
  • Natural coconut shell carbon filter


  • It is pretty expensive
  • It takes a while to set up

5. Express Water RO5DX Reverse Osmosis Filtration

Express Water RO5DX Reverse Osmosis Filtration is the best product for money value on our review list. It comes at a relatively affordable price for its high performance and reliability. This RO system has steady flow rates of up to 8 GPM to guarantee ready-to-drink water during on-demand applications.

It purifies up to 50 gallons of tap water per day. Thus, it is a good option for big households with up to six members.

Express RO5DX Water Filter Review

The system’s high-tech filtration media gives you pure water for multiple uses at home. It can be for cooking, washing utensils, brewing coffee, or even making ice cubes.

The filtration media are pretty durable, and you’ll only need to replace them twice a year. However, you can replace it after four months if you experience heavy pollution in your region.

Another feature that we like in this reverse osmosis filtration system is compatibility. Whether you’re moving houses or just experienced an earthquake, you can upgrade or downsize it to fit your needs. You can even use the RO system on another machine. However, the quality of your drinking water may drop if you use the wrong filtration media.

The leak detection system shuts the valve in case of an overflow. This can help you save up to 1,100 gallons of water per year. Lastly, you don’t need a plumber to install this RO filtration system. It comes with a brass feed adapter for a quick attachment. The packaging also includes two standard size under-sink pipes measuring ½-inch and 3/8-inch.


  • Warranty – One year limited warranty
  • Filtration Type – Reverse osmosis filtration
  • Filter Life (Till replacement) – Six months
  • Filter Stages – Five stages
  • Capacity – 4 gallon storage tank
  • Certifications – Certified to NFS /ANSI standard 58
  • Micron Rating – 1.0


  • Lifetime technical support
  • Leak detection system
  • Reliable in on-demand applications


  • No money-back guarantee
  • A small storage tank

6. AquaTru Countertop Water Filtration Purification System

Lastly, you can go for AquaTru Countertop Water Filtration Purification System if you want a product that lasts long enough to guarantee your money’s value.

The filtration media will require a replacement after two years or 1,200 gallons, whichever comes first. Such longevity saves you a lot of money spent on replacement filters. Moreover, you’ll wait for months, if not a year, before doing any service or repair.

AquaTru Reverse Osmosis Review

Say goodbye to reverse osmosis systems that don’t alert you when you need a replacement or system malfunctions. This product takes the guesswork out of your filtration experience.

You’ll get a notification when the filters outlast their lifespan. The installation and replacement processes are pretty straightforward; you’ll finish the job in seconds.

You’ll also save costs of purchasing water bottles. A single filter medium will replace about 4,500 16 oz water bottles. That means less plastic waste in your bin to end up in the landfills. You’ll be contributing to a greener world and reversing the effects of climate change. Moreover, the system’s plastic construction material is BPA-free, with eco-friendly properties.

This system purifies your drinking water in four filtration stages. The first two steps feature carbon filters to trap dust and sediments. Excess chlorine also gets trapped at this stage to improve taste and odor. The third stage features an RO filter to reduce lead, uranium, chromium 6, nitrates, and arsenic. The last VOC filter removes organic contaminants.


  • Warranty – Limited warranty
  • Filtration Type – Reverse osmosis
  • Filter Life (Till replacement) – Two years
  • Filter Stages – 4
  • Capacity – 1,200 gallons
  • Certifications – Certified to NSF standards
  • Micron Rating – 1.0


  • Quick installation and replacement
  • Four filtration stages
  • Filter replacement alert


  • Relatively costly
  • It might leak

What is a Reverse Osmosis System?

A reverse osmosis (RO) system is a water filter that leverages a partially permeable membrane to trap unwanted molecules, ions, and large molecules from your water source. It can be drinking water from municipal supplies or a private well.

The solute (filtered materials) remains on the pressurized side of the membrane while the pure solvent flows to the other side and collects on the top container. RO systems have high efficiency in trapping multiple contaminants. Thus, you can use these modes at home or in the office for mid-sized entities of up to ten employees.

How Does a Reverse Osmosis System Work?

High-quality reverse osmosis systems purify drinking water in multiple stages. Some will do so in up to stages, but ultrafiltration still works in three steps. Water enters the system and comes into contact with a sediment pre-filter medium to trap excess chlorine and silt or dust particles. 

The system then forces the sediment-free water down a semi-permeable membrane to trap Total Dissolved Solids (TDS). In the last stage, TDS-free water passes through a post-filter for polishing and ultrafiltration before flowing out of the system through a dedicated faucet.

Benefits of a Reverse Osmosis System

You’ll likely experience the following benefits after installing the best reverse osmosis system in your kitchen:

Get multiple health benefits at a relatively affordable initial investment. An RO filtration process traps microorganisms, bacteria, and impurities such as chemical contaminants to keep your family healthy throughout the year.

Experience improved water taste and order. A high-quality RO system will remove all prevalent contaminants that cause a foul smell and odd taste in drinking water.

Enhance a greener environment for natural processes. Installing a high-quality RO system in your home reduces bottled water dependency. A filter medium prevents about 700 plastic water bottles from ending up in your waste bin and finally in the landfills.

What Should You Look for When Buying this Product?

Having these considerations in mind will help you make an informed purchasing decision:

Type of Contaminants /Filtration Target

Which contaminants are prevalent in your region? Different RO system brands target specific pollutants. Also, they operate optimally at certain conditions and contaminant concentrations. 

You would want to test a sample of your water source in a local laboratory before buying an RO system. That way, you’ll get a product that exceeds your purification needs and expectations. You can also get a system that tests your water instead of taking samples to the lab.

Online Vs. Physical Stores

Buying from an online store always comes with perks that a physical store cannot offer. For instance, the reduced cost of operations translates to huge discounts and complimentary after-sale services such as free shipping and delivery costs. 

Moreover, you’ll likely browse an extensive catalog that gives variety for aesthetic preferences. Most importantly, you’ll purchase from the comfort of your living room.

Technical Assistance

A brand that offers ongoing technical assistance sounds like a good plan if you want to save unnecessary repair, service, and maintenance costs. While most brands will include technical support in the warranty terms, some give up to a lifetime membership. You only need to make the call, and the technicians will be at your doorstep in minutes.

Factors to Consider When Buying a Reverse Osmosis System

Besides the above considerations, it will also help if you have these factors in mind to point you in the best reverse osmosis system:

Container Size

The size of the upper container varies in different systems and ranges from three to 14 gallons. Even so, the actual size or capacity of the water reservoir depends on the air pressure inside the tank. Other factors that affect a container’s size include a metal bladder. 

To gauge the right container size for your household application, you’ll need to subtract about a gallon from the indicated capacity. For instance, the actual capacity of a 5-gallon storage tank is four or 3.5 gallons.

Water Waste

The main criticism facing reverse osmosis systems is that they waste a lot of water. Remember, RO systems remove contaminants from your drinking water in solvent forms, unlike in standard filters where the pollutants come out as solids. 

For instance, you can get a low-quality system that gives you a staggering three to 25 gallons of brine per gallon of filtered water. If you do the calculations, such a system can be relatively expensive to own and maintain in the long haul. Get a system that gives you higher filtered water: wastewater ratio to save on energy bills.


Another critical factor to consider is a system’s certifications. NSF or ANSI marks are the prevalent standard certifications from RO systems in the USA. Some products will also include WQA and IAPMO logos. 

Even so, be keen because some symbols represent certified components only and not the system as a whole. Some manufacturers will reveal this information in the product’s description, but others will assume that you already know.


Flexible warranty terms cover you from manufacturing defects. Don’t make the mistake of installing an RO system that comes with unclear warranty terms. You don’t want to spend a fortune on expensive repair and maintenance costs while the manufacturer can do that for the first few years. 

Moreover, an RO system with a limited warranty is of high quality and will likely reflect your money’s value.

High-Pressure Pump

An RO system should have minimum water pressure of about 50 psi for a trusted filtration process. However, most home products have a pressure range of about 30 to 80 psi. You need a high-pressure R0 system to ensure a continuous outflow of filtered water, even in on-demand applications. If your tap has fluctuating pressure rates, you would want to get an RO booster pump to increase the pressure by up to 30 psi.

Filter Longevity

The more often you replace the filtration media, the more expensive it gets to own and maintain an RO system. Buy a system whose filter media have a prolonged lifespan of up to a year or two. However, you may need to replace the filters sooner than expected, depending on trapped contaminants and the frequency of use.

Ease of Installation

Lastly, you would also want to consider the installation process. Purchasing a high-quality RO system already comes at a relatively high price. You don’t want to spend more on a professional plumber. 

Additionally, you don’t have the whole day to watch endless YouTube videos simply because your new system won’t set up. Go for a product that comes with easy-to-read and follows installation guidelines. Everything should be DIY unless you’re installing a high-capacity water filter for big household applications.

Wrapping It Up

An RO system removes contaminants from your drinking water in at least two passes for ultrafiltration. These systems are relatively affordable than whole-house purifiers. All the systems listed on this review guarantee up to 99.99% chlorine, TDS, and other contaminants removal. 

Even so, each product is unique and will cater to varying needs and preferences. For instance, a system that works well in a bungalow may not function optimally in an apartment. Thus, consider the specifications and product description from our review to get a system that matches your needs. Also, kindly note that buying from reputable stores such as Amazon guarantees warranty benefits. Click on individual product links to see the latest prices from Amazon.

The H2Home Lab team is dedicated to helping you find the best solutions to your specific water needs, as well as provide troubleshooting tips and guides for water filtration, heating, softening and plumbing. We hope you will find the info you need on our site from any one of our buying guides or subject matter articles.