8 of the Best Reverse Osmosis Systems for Home Use in 2024

We’ve spent 70+ hours of research and testing to identify the best reverse osmosis system for home—so that you don’t have to.

Updated: January 5, 2024
Jeremiah Zac


Our Choice for Best Reverse Osmosis System for Home

  Tankless design - but doesn't require electricity
  500 GPD
  10 X more water efficient
  Clean, space-saving design
  1-year warranty

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Brondell RO System

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The best reverse osmosis systems for homes have an efficient flow rate, easily-replaceable and accessible cartridges, durable build and fittings, and a good factory warranty. Some of the top brands are Pentair, Crystal Quest, Aquasana, Homemaster, and Brondell.

With the numerous brands of reverse osmosis system on the market, it can be difficult to narrow down the best choice for your home.

Nothing is worse than investing a large sum of money into a system that isn't quite specific to your needs, or even worse, is faulty.

While the science behind reverse osmosis is straightforward and doesn't differ much between brands, there are other features that might cause the decision-making process to be more involved.

Tankless vs tank systems, 4-stage vs 6-stage, and warranty are all factors that should be considered.

Some might be important to you, while others might be an upsell.

This article breaks down the different features among the most popular and reliable reverse osmosis brands to help you better device which is best for you.

In this article, we'll cover:

  • What is the best reverse osmosis system for home use and where can I purchase one?
  • The science behind Reverse Osmosis - stages and components of an RO system
  • The benefits of using an RO system and things to consider when purchasing one
  • How to install and care for your RO system

Best Reverse Osmosis System Comparison Chart

Brondell RO System

Brondell Circle RO

  Tankless design but doesn't require electricity
  500 GPD
  10 X more water efficient
  1-year warranty


  400 GPD
  7 Stages


  600 GPD
  4 Stages


  3.2 Gallon Tank
  100 GPD
  5 Stages


  3.2 Gallon Tank
  32 GPD
  6 Stages

Home Master RO System
Home Master

  3.2 Gallon Tank
  75 GPD
  7 Stages


  3.2 Gallon Tank
  75 GPD
  4 Stages

Crystal Quest

  3.2 Gallon Tank
  50 GPD
  6 Stages

What are the Best Reverse Osmosis Systems for Home Use?

The best reverse osmosis system for a home would be one that provides an efficient flow rate, easily-replaceable and accessible cartridges, durable build and fittings, and a good factory warranty.

Brands such as Pelican, Crystal Quest, Aquasana, Homemaster, and Brondell provide just that.

Our Best Choice

  • 4 Stages
    1. Sediment Filter
    2. Pre Carbon
    3. RO Membrane
    4. Post Carbon
  • Pressure: 40-120 psi
  • Tankless design - but doesn't require electricity
  • 500 GPD
  • Patented water-saving technology - 10 times more water efficient
  • Clean, space-saving design
  • 1-year warranty
Brondell RO System

Brondell's Circle reverse osmosis system features four essential stages, including the sediment filter, the pre-carbon filter, the RO membrane, and the post-carbon filter.

The Circle can handle a wide range of water pressures at 40-120 psi. It also has a clean, space-saving design. At 13" x 9" x 16", the rectangular tower doesn't have any filters or tubing exposed and fits nicely underneath the sink.

What makes the Circle unique is its utilization of tankless benefits without requiring electricity to operate as most tankless systems do. Instead, it uses a patented smart valve and flexible reservoir to maintain a high flow rate while saving ten times more water than a traditional tank system.

Our experience with the Brondell Circle

I’ve had my Brondell RO for over two years, and it’s been used entirely for drinking and cooking. I also have other means to purify water in the kitchen, such as a Berkey and some pitcher filters, so it isn’t the only thing used for clean water.

But when it comes to filling a large pot for soup, washing vegetables, or a quick glass of water to drink, the Brondell is my go-to.


Installation was easy. It takes up about the space of a desktop computer and rests snuggly in the back corner under the sink. The color-coded water lines make it easy to determine the inlet, outlet, and drain lines.

A simple modification to the main water line by adding the provided t-valve allows for water to feed into the RO system. The only other modification done to the plumbing was to drill a small hole in the drain pipe to connect the drain line.

Finally, the outlet connects to a nice chrome faucet that sits next to the main faucet on the kitchen sink.

Water quality

The water tastes great. Using a TDS meter, the reading comes up between 21 to 29 ppm when newly installed or after filter replacement. In comparison, the tap water reads about 390 ppm. TDS of less than 50 ppm is considered safe drinking water, while anything above 300 is considered high.


The LED light on the faucet makes it convenient to know when to replace a cartridge rather than keeping track of the months or relying on taste. I’ve replaced the RO membrane once and the other filters three times each. Replacement is easy, remove the outer shell and unscrew the filters individually.

Brondell's vertical tankless design is one of the best looking units on the market

The replaceable cartridges are easily accessible through the main door

  What we like most about the Brondell Circle

While the Brondell RO is technically a tankless system, it doesn't require electricity like most tankless units. Instead, it uses a flexible reservoir to pressurize water and a patented smart valve to ensure maximum efficiency. This unit combines the best of traditional tank and tankless units into one efficient system.

The end result is that you'll waste less water, you won't need to rely on electrical power, and yet you'll have a very high flow rate for an RO system. The 4-stages of filtration cover all of the contaminants any homeowner will need to be concerned about, and the cartridges are super easy to remove and replace. Plus, it's the best-looking system available, in our opinion. Now, that's hard to beat.

  What we don't like

The 1-year warranty seems a bit shorter in comparison to the longer warranty policies of other brands.

  Is it for you?

If you prefer the idea of a space-saving tankless system but don't want the burden of using more electricity for it, the Brondell Circle brilliantly combines the benefits of both.

  • Smart TDS monitoring panel 
  • Tankless Design
  • 400 GPD Fast Flow
  • 1:1 Water Waste Ratio
  • 7-stage Filtration
  • Automatic Flushing

Waterdrop RO

Waterdrop was founded in 2015, addressing increasing water quality concerns in the United States.

Waterdrop’s G3 Reverse Osmosis system improves upon the traditional RO design by introducing many innovative features and solving common problems. A common issue with most RO systems is that there tends to be an excessive amount of water wasted as the RO system is used. The G3 addresses this issue with its 1:1 Low Drain Ration system, saving on water usage by 300%.

While most conventional RO systems are known for their relatively low output, the G3’s fast flow system provides an unprecedented 400 gallons per day, that’s 1 cup of water every 12 seconds.

The seven-stage filtration system includes a pre-sediment filter, a post-carbon filter, and 3-layer reverse osmosis membrane, all responsible for removing chlorine, sand, rust, solids, and other impurities. Reduces TDS, limescale, heavy metals, bacteria, viruses, and more than 1,000 other harmful contaminants.

The G3 water drop has a smart faucet design, automatic flushing, and digital TDS meter.

The Waterdrop G3 comes with a smart faucet that indicates when the filter needs to be changed via an LED light

  What we like most about the Waterdrop G3

The Waterdrop boasts of a 1:1 drain ratio, lower than most traditional RO systems. This means that the G3 wastes 300% less water during its flushing cycle than other RO systems. Because RO systems are notorious for wasting water, this is a factor well worth highlighting.

The G3 also has one of the sleekest designs for an RO system. It looks so good we'd almost rather have it displayed on the countertop instead of keeping it under the sink where it's supposed to be.

  What we don't like

There's a bit of a noise when the unit is operating but it isn't any louder than most idle kitchen appliances like the fridge.

  Is it for you?

For those who want the most innovative and intelligently designed RO system which will provide clean water at high output without waste, this RO system is for you.

  • 600 GPD Flow Rate
  • 2:1 Water waste ratio
  • Tankless Design
  • Easy Installation
  • 4-stage Filtration
  • 180-day Satisfaction Guarantee
  • 5-year warranty


NuAqua Systems is a California-based distributor of high-quality water purification products for residential and commercial use. They have a team of experts that ensure all of their purification systems undergo rigorous testing, thus every one of their products are of the highest caliber. And with a wide network of qualified manufacturers, NuAqua is able to deliver the highest quality filters at very competitive prices.

As revolutionary as modern RO systems are, one of the chief complaints about home RO systems is the waste factor. Many RO systems are quite inefficient in conserving water and can often cause a noticeable increase in water expense. NuAqua’s Efficiency Series RO system provides an amazing 2:1 pure to waste factor. Meaning, twice as much clean water is preserved for the amount of unpurified water that is expelled by the system. This is a much higher ratio than many traditional RO systems that operate at a 1:3 pure to waste ratio.

Aside from the water efficiency factor, the Tankless RO has a unique compact design that won’t cause clutter under the sink. It’s ultra-quiet and its parts are easily interchangeable.

At 600 GPD, this RO system is fast enough to provide continuous clean water for any household size.

The tankless system has 3 chambers where the filters are kept

Each filter can be easily removed and replaced with a twist-lock mechanism

  What we like most about the NuAqua Tankless RO

At 600GPD and with a 2:1 water waste ratio, this RO system is both the most water efficient and the fastest flowing system on the list. While most RO systems tend to waste water, this is the only system on this list that actually preserves more water than it wastes.

And at 600GP, it has the highest flow rate of any system on this list as well.

  What we don't like

While the NuAqua System does have much to boast about, it is a fairly new brand in comparison to other long-standing brands in the water industry. Thus, it's difficult to say how the quality will hold up over time. Hopefully, the 120-day guarantee and 5-year warranty covers most of the skepticism newcomers may have.

  Is it for you?

If you’re interested in a modern RO system that wastes much less water than traditional systems and provides an incredible 600 GPD at an affordable price, then the NuAqua Tankless RO is definitely for you.

  • 100 GPD Flow Rate
  • Easy Installation
  • 5-stage Filtration
  • 180-day Satisfaction Guarantee
  • 5-year warranty

Building on the Tankless system’s efficiency and high-output profile, the Platinum 5-stage RO system by NuAqua adds some very important features.

With 5-stages, this RO unit provides a series of filters that ensure the purest water possible. The stages include: a sediment filter responsible for removing particulates, an activated carbon filter responsible for removing chlorine and pesticides, a carbon block filter responsible for removing pathogens and heavy metals, the RO membrane itself, and a post filter gives it a great taste for drinking.

The high-absorption filters last 25% longer than most traditional filters. And with a 3.2-gallon storage tank, this RO system will provide consistent pressure with high output. At 100 GPD, it provides a higher flow rate than most 5-stage RO systems in its class.

NuAqua provides an easy installation guide and 180-day satisfaction guarantee for all its products.

The 5-stage filtration system consists of 2 carbon filters, a sediment filter, an RO membrane, and a post filter

When fully assembled the RO unit rests underneath the sink and connects to the water line as a point-of-use system

  What we like most about the Nu Aqua RO System

The HydraCoil filter (Stage 2) is unique in that the carbon element has a 50% higher absorption rate than standard carbon block filters. This is due to the high-pressure processes in which the carbon media is made. The result is a critical stage in the RO process that removes 99% of the contaminants passing through the system. This feature is what makes the Nu Aqua RO unique.

  What we don't like

Being a fairly new company, time will tell whether the build quality of Nu Aqua's RO systems can stand up to the other RO systems that have been around longer. Based on what we've seen, Nu Aqua's products are very robust, and the 5-year warranty and 180-day guarantee are definitely a bonus.

  Is it for you?

If you’re interested in a 5-stage RO system for the purest quality but want something with a higher flow-rate than the traditional 50 GPD, this RO system is for you.

  • 7 Stages
  • 75 GPD
  • Pressure: 40-90 psi
  • Filter housing is replaced with filter
  • Larger fittings and tubing for faster flow
  • Non-electric pump for improved efficiency
  • 5-year limited warranty
  • Made in USA

Home Master RO System

The 7-stage home reverse osmosis system by Home Master features an upright design with modular filters for easy access and replacement. While most RO systems require filters alone to be replaced periodically, the Home Master system replaces the entire module.

Modules are required to be replaced periodically anyway, so the Home Master system allows you to do so with the filter. With larger fittings and tubing, along with a non-electric water pump, the Home Master system has a much faster flow and is much more water-efficient than most RO systems.

The pressure tank stores the purified water for future use rather than requiring the RO system to operate whenever the tap is turned on

The Homemaster package includes a faucet and all the fittings

Because the tank is large, the actual RO unit is more compact than most traditional RO systems, saving some space.

  What we like most about the Homemaster RO

Most of the traditional tank-style RO systems sacrifice water efficiency for energy efficiency, but the Homemaster RO is able to achieve both. With its permeate pump upgrade, the water efficiency reaches a 1:1 waste ratio, making it one of the most water efficient RO units that isn't tankless.

  What we don't like

Traditional RO systems can take up a lot of space, especially with the tank. If you don't have a lot of space under your sink, things can get pretty tight.

  Is it for you?

If you prefer the traditional RO design with a pressure tank due to the lack of need for electric power but don't want to waste too much water, the Homemaster RO is one of the most water-efficient units that uses a tank.

  • 6 Stages
    1. RO membrane
    2. Activated Carbon
    3. Catalytic Carbon
    4. Ion Exchange
    5. Sub-micron Filtration
    6. Remineralization
  • Live phone support
  • 2-year warranty
  • 90-day guarantee
  • Provides 35 Gallons per day
Aquasana RO

Aquasana is a manufacturing company based out of Austin, TX, and specializes in innovative filtering technology.

This reverse osmosis system removes contaminants through the RO membrane and then uses claryum technology to further filter the water.

Through ion exchange, heavy metals such as lead and mercury are completely removed. Finally, ph balance is raised as healthy, essential minerals are reintroduced to the water, providing a clean, crisp taste.

This combination of reverse osmosis and post filtration removes 95% of fluoride from the water supply.

Aquasana's RO system includes the pressure tank, RO system with 4-stage filtration, smart faucet, and all connections

Aquasana's filtration cartridges are easy to remove and replace

  What we like most about Aquasana's RO System

Aquasana's patented Claryum filter combines activated carbon with ion-exchange to produce some of the best tasting water an RO system can produce. Its multi-layered filtration process is capable of removing a wide variety of elements including fluoride.

  What we don't like

The flow rate of 35 GPD is lower than some RO systems making it ideal for smaller homes

  Is it for you?

For those who want a highly effective, great-tasting RO system with great customer service and warranty, Aquasana’s OPTIMH20 provides just that.

  • 4 Stages
    1. Sediment Filter
    2. Carbon Filter
    3. RO Membrane
    4. Post-Carbon
  • 75 Gallons per day
  • Live phone support
  • Lifetime warranty
  • 6-month money-back guarantee

Springwell RO system

Springwell’s under-sink RO system is a simple and effective option for home reverse osmosis filtration. The four stages provide all essential filters: sediment, carbon, RO membrane, and post carbon.

The sediment filter blocks large particles and silt, and the carbon filter removes chlorine, chloramine, herbicides, and pesticides.

The RO membrane effectively does what the other filters cant’ and removes dissolved solids and heavy metals such as lead, mercury, arsenic, fluoride, iron, and aluminum. Finally, the post carbon filter provides a final cleansing and improves taste.

Springwells RO system provides a high-output flow rate at 75 gallons per day and offers a 6-month money-back guarantee.

  What we like most about Springwell

The most outstanding feature about Springwell is its lifetime warranty. No other RO system we've come across has a warranty this strong and it says a lot about the company and its support for its customers. As long as the RO unit has been used properly, you can inquire with Springwell for defects in the system at any time after your purchase and they'll have you covered.

  What we don't like

The option to include a UV purifier onto the system is pretty expensive.

  Is it for you?

Springwell’s RO system is perfect for those who use large quantities of water throughout the day and want to ensure the cleanest water possible at all times. If customer guarantee is important to you, Springwell's RO is the only system with a lifetime warranty.

  • 50 Gallons per day
  • 3.2 Gallon tank
  • 6 Stages
  • 15 levels of purification
  • 1-year warranty

Crystal Quest RO Under Sink

Crystal Quest features an under-the-sink, complete RO system which delivers 50 gallons of perfectly purified water per day through a series of complex filtration layers.

Crystal Quest has designed a system which involves 15 levels of purification resulting in the absolute cleanest water possible. With a 3.2-gallon pressurized holding tank, this RO system will ensure properly pressurized water at all times. All replacement filters can be purchased through the Crystal Quest website.

  What we like most about Crystal Quest's RO

While marketed as a 6-stage system, Crystal Quest's RO actually passes through 15 stages of filtration. From activated carbon pre-filters to multiple ultra-filtration membranes and its patented Eagle Alloy media, the robust system removes a very large variety of contaminants.

  What we don't like

Because of it powerful filtration capabilities, the Crystal Quest RO has a slightly lower flow-rate at 50 GPD.

  Is it for you?

For those interested in the highest level of purification ingenuity, Crystal Quest provides a system that utilizes all of the latest innovations in reverse osmosis technology. If you want a variety of contaminants removed but don't mind a lower flow rate, this might be for you.

Things to Consider when Purchasing an RO System

reverse osmosis unplugged

RO systems can remove a wide variety of contaminants but depend on several factors that determine their effectiveness. Here are some things to consider when purchasing a reverse osmosis system.

Tank vs tankless system

While both systems use an RO membrane similarly, the main difference between tankless and tank systems is how the water is delivered. In a traditional tank system, the purified water is stored in a pressure tank for immediate availability whenever the tap is turned on. A tankless system, however, uses a water pump to push water through on demand.

A tankless system is generally more water-efficient but requires electricity. A traditional tank system is generally much quieter and less expensive but occupies much more space.

Both systems have their pros and cons. Their key points are listed below.

Traditional RO System with Pressure Tank

  • Doesn't require electricity
  • Pressurized water eliminates the need for a booster pump
  • The tank serves as a storage container
  • Less expensive than tankless systems
  • Quieter - no pump involved

Tankless RO System

  • Occupies much less space
  • No need to wait for tank to fill in-between uses
  • Delivers water at a much higher flow rate
  • Wastes much less water than traditional tank systems
  • No need for regular tank cleaning and maintenance

The source of water

Most residential homes will get their water from one of two sources: city water or well water.

Those who live in urban areas will likely get their water treated by the city and have fewer contaminants. However, trace chemicals, disinfection byproducts, and pharmaceuticals can still make their way through the treatment system and into the home's water supply.

For homes that rely on city water, a basic reverse osmosis water filter system is sufficient for providing clean water.

Homes that rely on private wells won't have pre-treated water and are responsible for purifying it themselves. Groundwater can harbor high levels of minerals and can contain microorganisms such as bacteria.

For well owners, it is best to incorporate a UV system to eliminate the threat of microorganisms. Read our article on UV water purifiers for home use.

Stages of filtration

RO systems often have multiple stages of filtration, with each stage using a different medium to target certain contaminants.

Three-stage reverse osmosis systems are the most common and are sufficient for most home applications, consisting of a pre-filter, RO membrane, and post-filter.

Those with high levels of iron, sediment, or bacteria in the water may want to consider RO systems with additional stages.

Some RO systems feature an additional sediment pre-filter or UV purifier to address these specific contaminants.

Water pressure

RO systems require sufficient water pressure to push the water through the membrane. Homes that rely on city water generally have adequate pressure due to the pumping system provided by the water facilities.

However, well water owners are known for having lower water pressure due to the complexities of private water pumps. Incorporating a pressure booster may help increase the water pressure to an adequate level for the RO system to function properly.

Around 60 PSI is ideal for a home reverse osmosis system to run properly. Anything below 40 PSI is considered insufficient and may require the assistance of a booster pump.

Membrane quality

The RO system's ability to effectively remove contaminants from water is known as the rejection rate. In other words, it indicates how much of the total volume of contaminants are rejected from the water supply. The higher the rejection rate, the more effective the RO system at purifying water.

Many RO systems claim a 99% rejection rate when that number is likely an average of the total amount of contaminants removed.

The WQA and NFS are nonprofit notified bodies based in the US that test and certify RO systems. RO systems with either of these ratings are generally considered reputable.

At any rate, the water quality can be gauged using a total dissolved solid (TDS) meter to confirm its purity.

Water quality

While RO systems are extremely effective at eliminating a variety of contaminants, not all water sources are necessarily in need of one.

Some well water sources can be high in calcium and magnesium, contributing to hardness. In this case, a water softener may be better suited for the source.

Other water sources, such as surface water, often contain high levels of biological contaminants, such as viruses, bacteria, and protozoa. For rural homes and cabins that are pumping water from a lake, a UV purifier will be necessary.

But for homes that rely on city water with unknown traces of chemicals, lead, and pharmaceuticals, or for rural homes whose well water contains trace amounts of arsenic and a variety of other chemical pollutants, nothing is better than reverse osmosis.

Flow rate

The term 'flow rate' refers to the amount of water that can be provided in a given time. Usually measured in gallons per day (GPD), RO systems with a tank can have a flow rate of 40 to 60 GPD. For most homes, this can provide enough water for all drinking and cooking needs.

Tankless RO systems can have much higher flow rates, up to 600 GPD, providing enough water for other needs, including showering and washing.

Before choosing an RO system, it is important to determine what the system will be used for and how many people will be using it. If the RO system is only used for drinking and cooking, a system with a lower flow rate may suffice. Needs that involve washing, bathing, and more intensive demands will require a higher flow rate.

The number of people involved in a household will also affect the flow rate. The more people using water, the higher the flow rate needs to be.

Budget and maintenance costs

There are two types of costs you should consider – the initial cost and the maintenance cost. The initial cost is the initial purchase price of the system, whereas the maintenance cost involves the replacement of filters and faulty parts.

RO systems range in price depending on a number of features. RO systems with multiple filtration stages, including remineralization filters and UV purifiers, will be costlier than a simple 3-stage system.

Tankless RO systems that run on electricity and provide flow rates of up to 600 GPD are costlier than tank-based systems with a modest 50 GPD.

Your choice should be based on your needs so that you don't overspend on unnecessary features that only complicate the process.

Replacement filters are something else to consider. The more filtration stages involved, the more filters there are to replace.

While the RO membrane itself can last up to 2 years before requiring replacement, other filters, such as sediment and activated carbon filters, might need to be replaced every six months or so, depending on usage.

How Does Reverse Osmosis Work?

reverse osmosis colored diagram

The technical definition of osmosis is the process of equalizing the concentration of particles in water by utilizing a permeable protein membrane.

What this means is when water passes through a membrane, the concentration of dissolved particles on either side of the membrane becomes equal.

In contrast, reverse osmosis involves applying external pressure to reverse the natural flow of water and prevent equilibrium from being formed.

Pressure is applied so that concentrated water is forced through the membrane allowing particle-free water to emerge on the other side.

That's the technical definition.

An easier way to understand how RO works is to think of the RO membrane as a really, really fine filter. It's so fine, in fact, that the pores only allow water molecules to pass through.

Therefore, larger molecules such as minerals, chemicals, and biological contaminants are left on the other side.

The end result is pure H20. This is why RO systems often re-introduce beneficial minerals such as magnesium and potassium via a post-filter.

  • (A) Applied Pressure
  • (B) Concentrated Water
  • (C) Dissolved Particles
  • (D) Membrane
  • (E) Clean Water
  • (F) Osmotic Pressure

Stages of Reverse Osmosis

A reverse osmosis system usually consists of three phases – pretreatment, reverse osmosis, and post-treatment.

Some RO systems may include additional stages, which are optional. As water travels through each stage, a different type of treatment process is applied before the water is ready to come out of the faucet for consumption.

We'll explain the purpose of each stage in this section:

  1. Sediment Filter - The dirty or contaminated water is first pre-filtered with a sediment filter to remove larger trapped particles, including rust and calcium carbonate.

    Sediments and other particulate matter like dirt, silt, and rust affect the taste and appearance of water.

    The sediment filter also acts to protect the filters that come after it by removing contaminants that could affect them. Because this filter is the first to come in contact with water, it requires the most frequent replacement and should be done so every six months with regular use.

  1. Carbon Filter with Activated Carbon - The water is pre-filtered with a carbon filter. The activated carbon filters out chlorine, oils, and trapped organic chemicals, which can attack and degrade the thin film composite membrane used for the reverse osmosis filter.

    The oils can plug the reverse osmosis membrane, and chlorine can eat the pores on the membrane, thus increasing the flow rate and allowing more contaminants to pass through as the pores on the membrane become larger.

    This filter should be replaced every year with regular use.

  1. Reverse Osmosis Membrane - This is where reverse osmosis takes place, removing most contaminants. The reverse osmosis membrane removes organic and inorganic compounds, including fluoride, arsenic, lead, parasitic cysts, and copper.

    It also greatly reduces impurities known as Total Dissolved Solids (TDS), which comprise inorganic salts such as calcium, magnesium, and sodium.

  1. Remineralizing Filter - As water purified by reverse osmosis is highly pure and slightly acidic, a remineralizing filter is used to introduce healthy minerals, mainly calcium and magnesium, which also balances the pH and improves the taste.

  1. Storage Tank - This is where the water is stored after it has gone through the major stages of the purification process. In most systems, it is ready to be released through the faucet. Other systems might include additional stages.

  1. UV Filter (Optional) - The UV filter protects against biological contaminants by destroying microorganisms, including harmful bacteria, E. coli, viruses, fungi, and microbes.

    The UV rays penetrate harmful pathogens, destroying illness-causing microorganisms by attacking their genetic core (DNA).

  1. Color Changing Resin Deionization Filter (Optional) - The Color Changing Resin Deionization Filter removes all the remaining Total Dissolved Solids (TDS) from the membrane-filtered water.

    There is usually a small amount of TDS left in the water after being filtered by the reverse osmosis membrane.

    This stage is required when the water is to be used in aquariums, as lowering TDS for all aquatic animals is very important for osmotic regulation and hydration.

  1. Final Carbon Filter - The final carbon filter, also known as a “polishing” filter, removes any tastes and odors the water may have picked up from the storage tank.

    The slightly acidic water resulting from the reverse osmosis stage may dissolve some rubber in the storage tank, which the final carbon filter removes.

What Contaminants are Removed?

Reverse osmosis removes a variety of contaminants. Reverse osmosis has the capability to remove up to 99%+ of the dissolved salts or ions, particles, organics, bacteria and pyrogens from untreated water. However, reverse osmosis is not efficient enough to remove 100% of bacteria and viruses, so UV filters may be used with RO systems.

The following tables gives a summary of some inorganic salts removed along with their percentages.


Percentage Removed


85 - 94%


96 - 98%


94 - 98%


85 - 95%


60 - 75%


94 - 98%


95 - 98%


95 - 98%


94 - 96%


96 - 98%


95 - 98%


92 - 96%


94 - 98%


96 - 98%


85 - 92%


94 - 98%


95 - 98%


95 - 98%


84 - 92%


85 - 92%

Basic Components of an RO System

RO systems consist of five basic components:

  1. Pressure Vessels and Membranes - Membranes are the fundamental parts of RO systems. Various proteins make up the membrane elements depending on the kind of water that is input and how clear the untreated water is.

    There are different membrane elements for brackish water, seawater, hospital-grade infection, and specific contaminants.

    The size and number of membranes required in a reverse osmosis system will depend on the size of the task – whether municipal, commercial, or industrial.

  1. Reverse Osmosis Skid - Reverse osmosis skids are used to make RO systems durable. These skids are a powder-coated, carbon steel frame used to mount all the components.

    It is designed and built to withstand the heavy vibration of high-pressure pumps.

  1. Cartridge Filter - Cartridge filters are used to pre-filter the water and remove particles that are large enough to damage the membranes.

    A five-micron spun polypropylene filter is usually used as the cartridge filter, but it can vary upon request. The cartridge comes in a durable casing to handle pressure from the main feed and booster pumps.

  1. Reverse Osmosis High-Pressure Pump - High-pressure pumps are crucial for the rejection rates of RO systems. High-grade pumps are essential for a feasible rejection rate in commercial and industrial settings.

    The high-pressure pump needs to be matched to the membrane size and quantity as well.

    In general, the higher the horsepower of the pump, the higher the rejection rates of the reverse osmosis membrane.

  1. Control Panel - A control panel is needed for the human operator to control the reverse osmosis system.

    Advanced PLCs or solid-state microprocessors are used depending on how advanced the controls need to be. In an industrial setting, a control panel can be used to control and manage multiple RO systems simultaneously.

In addition to these five basic components, other components can be built onto or into RO systems based on your requirements.

Reverse Osmosis Water Benefits

RO system on the wall

RO systems provide clean, refreshing water, and they have many benefits over regular filtration systems.

  1. Removes all types of contaminants - RO systems are 99% efficient in removing all types of contaminants to produce clean and safe drinking water. The semi-permeable membrane isolates contaminants from water, including bacteria, viruses, dirt, ions, and heavy metals.

  1. Removes odor from water - While regular filtration systems do not remove odor from water, RO systems have a carbon filter with activated carbon that attracts and filters out odor-causing contaminants such as chlorine and iodine.

  1. Very easy to maintain - While you are required to wash and rinse regular filtration systems often, the filters in RO systems are washed regularly by the system itself. The concept of reverse osmosis makes the system easy for households to maintain and keep running for a long time.

  1. Long-lasting and economical - RO systems generally last longer than regular filtration systems. As the membranes are washed by the rinse water itself, RO systems can last for a couple of years. RO systems are also very economical as they require minimal maintenance, unlike regular filtration systems that require regular maintenance.

  1. Option for UV Radiation - UV radiation is known to be the most effective method for disinfecting bacteria from water. While regular filtration systems do not use UV lamps, some RO systems may use UV lamps to kill bacteria and viruses.

  1. Removes inorganic molecules - Although regular filtration systems with carbon cartridges are unable to remove inorganic compounds, RO systems can filter out inorganic molecules with the membrane. Inorganic molecules such as inorganic phosphorus, inorganic carbon and inorganic nitrogen found in brackish water can result in the formation of hard water.

Inorganic chemical contaminants such as bleach and curing agents may also be present in the source water meant for domestic consumption.

Reverse Osmosis Installation Guide

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The installation process of RO systems is simple and can be done with little help.

Find the Best Location

RO systems are generally made to fit under the sink. You should choose a location that is convenient to operate. Keep in mind that the cold-water valve should be shut during the installation as the system has to be installed along the cold-water line.

Faucet Installation

You can easily mount your faucet if your sink has extra holes for faucets. If your sink does not have an extra hole, you will have to drill a hole. Be mindful of the material your sink is made from when drilling – whether stainless steel or porcelain. If the hole is covered by a chrome plate, simply remove the chrome plate and mount the faucet.

For convenience, the faucet spout should be allowed to move freely. Follow these steps to install the faucet.

  1. Insert the faucet stem into the hole

  2. If you are installing a non-air gap faucet, fit the flat rubber washer. Ignore this step if you are installing an air-gap faucet

  3. Slide on the big chrome base plate and the big rubber washer underneath the faucet body

  4. Slide the plastic washer from under the sink

  5. Screw on the brass hex tightly once the faucet is well aligned

Drain Saddle Installation

Place the drain saddle preferably at the highest possible point above the water in the trap and far from the waste disposal drains.

  1. Drill a hole of approximately a 1/4 inch in diameter through a side of the pipe once you identify the point of your drain saddle.

  2. Attach the drain clamp with its hole in line with the hole in the pipe

  3. Tighten the clamp well enough for easy removal when you want to do maintenance

Tube Connections

  1. The tank tube is connected from the filter to the tank valve.

  2. The faucet tube is fixed from the faucet bottom to the fitting adjacent to the tank and tightened firmly.

  3. The drain fitting is behind the membrane system. The drain tube is kept short and connected to the drain saddle.

Maintenance and Care

Proper maintenance can allow high-quality RO systems to last for many years. Proper maintenance involves regular filter replacements and an annual sanitization of the system. The sediment filter, carbon filter and polishing filter will have to be replaced annually while the reverse osmosis membrane can be replaced every two to three years. Note that failure to replace filters can cause damage to the system and decrease the water production.

Annual Sanitation

You may have to consult the owner’s manual for details on how to sanitize the system. These are the general steps:

  1. Turn off the main valve
  2. Drain out all the water from the faucet
  3. Detach the sediment and carbon filters
  4. Detach the reverse osmosis membrane
  5. Screw the housings back in place without the filters
  6. Pour 1 cup of hydrogen peroxide into the stage one housing
  7. Reattach the all the tube connections
  8. Turn on the main valve
  9. Let the system run through at least 2 cycles without the filters
  10. Turn off the main valve
  11. Install the new filters
  12. Allow the system to run through 1 complete cycle

Reverse Osmosis FAQs

How Much Water Do RO Systems Waste?

An RO system does use more water during operation than it does produce for drinking, but it’s actually far more water efficient than most household appliances such as washing machines and dishwashers. RO systems use water for self-cleaning and for washing away impurities. In terms of water bill expense, it equals to about 3 toilet flushes a day.

How Long Will a Reverse Osmosis Unit last?

If an RO unit properly maintained and its parts are replaced at their required intervals, it can last a lifetime. RO membranes typically need to be replaced every 3-5 years while each individual filter might need to be replaced annually.

Do Reverse Osmosis Units Require Electricity?

Reverse osmosis systems run entirely on water pressure, not electricity. Electricity will be required to power a UV lamp in the system includes one.


Reverse osmosis has proven to be an efficient and cost effective way of purifying water of bacteria, viruses, sediment, solvents, and chemicals. Many RO systems come with several additional stages for extra features and filtration. While some of these features are certainly beneficial, the core components of an effective RO system are the sediment and carbon filters, the RO membrane, and the holding tank. Be sure to select a system that best fits your needs and your budget.

Our Choice for Best Reverse Osmosis System for Home
  • 4 Stages
  • Pressure: 40-120 psi
  • Tankless design - but doesn't require electricity
  • 500 GPD
  • Patented water-saving technology
  • 10 times more water efficient
  • Clean, space-saving design
  • 1-year warranty

Thank you for taking the time to read our article on the best reverse osmosis system for home use. We'd love to hear your feedback in the comments section below. If you've found this article to be useful and are interested in learning more, be sure to sign up for our newsletter.

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ESP Water Products. (n.d.). 'How to Maintain Your RO System for Best Performance. Retrieved from https://www.espwaterproducts.com/blog/how-to-maintain-your-ro-system-for-best-performance/

H20 Distributors. (n.d.). Reverse Osmosis System Installation Guide - H2O Distributors. Retrieved from https://www.h2odistributors.com/pages/manuals/reverse-osmosis-installation.asp

How Stuff Works. (2008, May 8). How Reverse Osmosis Works. Retrieved from https://science.howstuffworks.com/reverse-osmosis.htm

Is Reverse Osmosis Wasteful? (n.d.). Retrieved from https://blog.uswatersystems.com/2011/05/is-reverse-osmosis-wasteful/

Pure Aqua. (n.d.). What is Reverse Osmosis & How does it work? Retrieved from https://www.pureaqua.com/what-is-reverse-osmosis-ro

Puretec. (n.d.). Puretec Industrial Water | What is Reverse Osmosis? Retrieved from https://puretecwater.com/reverse-osmosis/what-is-reverse-osmosis

Water Advise. (2016, June 25). Advantages Of A Reverse Osmosis Water System Over Other Purification Methods. Retrieved from https://wateradvise.com/advantages-of-a-reverse-osmosis-water-system-over-other-purification-methods/

Water Right. (n.d.). Benefits of Drinking Reverse Osmosis Water | Water-Right. Retrieved from http://www.water-rightgroup.com/blog/benefits-reverse-osmosis-water/

I'm Jeremiah, the owner of World Water Reserve. I'm a writer and researcher with a particular interest in sustainability and rural living, water scarcity, and innovative water purification methods. I utilize my multimedia and communication experience in the NGO and humanitarian fields to bring light to important topics. My passion is to educate others on the reality of the global water crisis and on ways to sustain themselves and their families in the midst of it.
Jeremiah Zac