Best whole-house RO

Best combined RO

Best under-sink RO

The Crystal Quest Thunder is a highly customizable whole house reverse osmosis system with a 300 gallon per day capacity and large storage tank.

Combining the Springwell CF1 with their point-of-use RO filter creates a tankless whole house system that targets filtration where it’s needed.

The APEC Essence is one of the most popular and affordable filters on the market. Install it under multiple faucets to protect the whole home.

Best whole-house RO

Best combined RO

Best under-sink RO

The Crystal Quest Thunder is a highly customizable whole house reverse osmosis system with a 300 gallon per day capacity and large storage tank.

Combining Springwell’s CF1 filter with their point-of-use RO system creates a tankless whole house system that targets RO filtration where it’s needed.

The APEC Essence is one of the most popular under-sink RO filters on the market and is affordable enough to install under multiple faucets.

Whole house reverse osmosis (RO) systems provide premium-quality drinking water at home – no matter the type or number of contaminants in the water supply.

By passing water through membranes with microscopic pores, RO systems offer the most comprehensive and powerful contaminant-removal of all home filters.

On this page, we’ve reviewed whole house RO systems by the features that matter most, including flow rate, tank size, water processing efficiency, and previous customer reviews.

We’ve also explained the differences between RO systems, and how to choose the right type for your home.

Whole House RO Systems – 2022 Full List

True whole house reverse osmosis systems:

Combination reverse osmosis systems:

Under-sink reverse osmosis systems:

  • 🏆 Most popular under-sink reverse osmosis system: APEC Essence

Which Reverse Osmosis System is Right for Me?

Reverse osmosis systems create premium drinking water, but they process water slowly, which means you can’t install them in the same way as other home filters.

There are three main types of RO systems that can be used in a whole-house capacity:

  • The first type is true whole house RO systems. These filters use a high-powered RO membrane and large storage tanks to process and hold enough water for all of your home’s needs.
  • The second type is combined RO systems, consisting of two separate devices. Combined systems use a carbon filter and/or softener on the main line, plus a smaller RO system and tank nearer the point of use.
  • The third type is standard under-sink RO systems. These affordable RO systems supply water to a single faucet and can be fitted under any sink used for drinking water.

The type of reverse osmosis system you choose should depend upon a few factors – most importantly, the quality of your water supply, and your household water demands.

  • If your water is not safe for use or consumption without treatment, you should use a true whole house reverse osmosis system.
  • If your water is safe but contains contaminants that affect taste, smell, or appearance, you can choose to use either a combined RO system or multiple under-sink RO systems.

If you’re on well water, or if you’re looking for a single filtration solution, a true whole house reverse osmosis system is also likely the better choice.

If you’re on city water, or if you’re looking for a tankless filtration solution, a combined RO or multiple RO approach is usually preferable.

Compare Whole House Reverse Osmosis Systems

Crystal QuestUS Water SystemsSpringWellHome MasterTier1AquasureAPECAquasanaExpress Water
Product nameThunder 300DefenderCF1 + RO SystemTMEssentialEssenceOptimH2O® ROExpress Water RO5DX
System designWhole house systemWhole house systemCombined systemCombined systemCombined systemCombined systemUnder-sink systemUnder-sink systemUnder-sink system
flow rate (GPD)300 GPD2000 GPD75 GPD / 9 GPM75 GPD50 GPD / 5.8 GPM75 GPD / 15 GPM50 GPD13.3 GPD50 GPD
Tank size165 gallons140 gallons3.2 gallons53 gallons3.2 gallons3.2 gallons4 gallons3.2 gallons3.2 gallons
Efficiency50%80%23%25% (50% with additional pump)33%33%33%17.90%33%
Unit SizeLargeLargeLargeMid-sizeLargeLargeCompactCompactCompact
Extra filtration stages
Sediment, Carbon, SMART Filter
Micron, UVCarbon + KDF, Sediment, Carbon pre & postSediment, CarbonIon exchange softener, Sediment, Carbon, Carbon postIon exchange softener, Carbon + KDF, Sediment, Carbon pre & post
Carbon, Sediment, Carbon pre & post
Carbon, Claryum cartidge, Optional remineralizer
Sediment, Carbon, Carbon pre & post

Key Features of Whole House RO Systems

Here’s an overview of the main features you should be looking into when shopping for a reverse osmosis system.

System type
Some RO filters are standalone systems with large storage tanks. Others are mounted under-sinks and are compatible with other filtration stages.
Flow rate
RO systems filter water slowly and can only process so many gallons per day. Pick a flow rate that won’t exhaust your storage tank.
Tank size
Water storage tanks keep a reserve of filtered water for on-demand use. The right size depends upon where in a plumbing system an RO system is installed. For reference, the average family uses 350 gallons of water per day.
Filter stages
RO membranes are powerful but delicate, and degrade when exposed to common materials like chlorine or calcium carbonate. Adding other filtration stages to a system improves membrane performance and lifespan.
Unit size
Not all homes have the space to house a large water storage tank. Pick an RO system that’s sized for your needs.
RO systems tend to cost more than other home filters, but they last for longer without maintenance. Other stages, such as carbon media cartridges, need replacing annually.
Water waste
Because they operate under pressure, all RO systems waste more water than they purify. The best devices keep water waste to a minimum.

Best Whole House Reverse Osmosis System

True whole house reverse osmosis systems consist of powerful reverse osmosis membranes, large pumps, and 100-plus gallon storage tanks to provide all the water a home needs.

Most often, these systems are installed at the point where the mains water supply enters the home. They also allow customers to choose different power levels and tank capacities, so you can find a system that produces the right amount of purified water for your needs, without overspending.

People choose true whole house RO systems because they offer impressive filtering power in a single system that’s relatively easy to maintain. Membranes last for years, while carbon and sediment filters can be simply switched out annually.

Products like the Crystal Quest Thunder cover every common contaminant, for all sizes of homes. They take up a significant amount of floor space and have higher retail price tags, but there is no more comprehensive way of protecting water quality:

  • Flow: 300 GPD
  • Tank size: 165 gallons

  • Efficiency: 50%

  • Price: $3465

  • Rating: ★★★★★

Best Whole House RO System

Crystal Quest Thunder 300

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The Crystal Quest Thunder 300 is one of the few reverse osmosis systems on the market that’s specifically designed for whole-house residential use – meaning it’s capable of providing enough RO-filtered water for every faucet, shower, and appliance.

With multiple storage tank capacities, flow rate, and filtration stage options, it’s easy to customize the system for the size of your home and the quality of your water. The included pump and float switch ensures that the system responds immediately on demand.

Another popular and powerful whole house RO system is the Defender from US Water Systems:

  • Flow: 2000 GPD
  • Tank size: 140 gallons

  • Efficiency: 80%

  • Price: $7750

  • Rating: ★★★★☆

Runner Up Whole House RO System

US Water Defender

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The Defender from US Water Systems is another fully adjustable true whole-house reverse osmosis system that’s cost-effective, reliable, and environmentally responsible — in-house engineering makes it 80 percent efficient, meaning it wastes only 1 gallon for every 5 processed.

Previous customers rate the Defender’s ability to deliver water year after year thanks to stainless steel housing, industrial pumps, strengthened fittings, and a UV purifier included as standard. The GPD and storage tank options cater to the most water-demanding households.

Best Combination Reverse Osmosis System

Other homeowners may be unwilling to spend upfront for a true whole house RO system or don’t like the idea of using such a large water storage tank.

For these people, a combined reverse osmosis system is a practical solution. A basic carbon filter tank and/or water softener, while a smaller RO filter covers drinking faucets further into a home’s plumbing.

Most often, these systems are used when source water quality is good enough for showering and laundry with only basic filtering or softening. Reverse osmosis filtration is reserved water that’s used for drinking and cooking.

People choose combined RO systems because they target filtering power where it’s most needed. By only using reverse osmosis membranes on drinking water, there’s no need for a large storage tank, and flow rates are less likely to be affected.

Products like the SpringWell CF1 + RO Filter protect bathrooms from chemicals and water smells while ensuring drinking water is free from heavy metals and minerals:

  • Flow: 75 GPD / 9 GPM
  • Tank size: 3.2 gallons

  • Efficiency: 23%

  • Price: $1259

  • Rating: ★★★★★

Best RO System + Carbon Filter

SpringWell CF1 + RO

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SpringWell offer a combined approach to whole-house RO filtration with their CF1 whole-house tank and 4-stage under-sink RO filter. The CF1 goes on the main water line to filter all household water for bad smells and tastes, discoloration, and common contaminants like chlorine, pesticides, and sediment.

At your kitchen sink, the SpringWell RO filter adds extra layers of protection against health risks like lead, heavy metals, and microorganisms. Using a combined system keeps your drinking water pure and your household supply flowing fast without the need for a large storage tank.

Alternatively, the Tier 1 Everyday Series combines point-of-use reverse osmosis filtering with a salt-based whole house water softener:

  • Flow: 50 GPD / 5.8 GPM
  • Tank size: 3.2 gallons

  • Efficiency: 33%

  • Price: $697

  • Rating: ★★★★★

Best RO System + Softener

Tier 1 Essential Series

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Two of the most popular types of home filters are water softeners and reverse osmosis systems, thanks to the way they target highly common US drinking water contaminants. Softeners use pure salts to attract and remove hard water minerals like calcium and magnesium from the water supply, while the micro-pore membranes and carbon cartridges in RO systems screen harmful metals and chemicals from water, while conditioning it for taste, smell, and appearance.

Tier 1 is a widely-used value filtration brand, who offer standard softening and RO solutions — combined here in the essential series. At 48,000 grains, and complete with a digital metered tank head, Tier 1’s softener has a large enough capacity to deal with moderate-to-high water hardness, and the ability to track consumption and auto-manage regeneration.

The Tier 1 reverse osmosis filter comes with all the standard pre- and post-filtration stages, a 3.2 gallon under-sink storage tank, and can produce 50 gallons of water per day.

Alternatively, the HomeMaster TM has a moderate flow rate and a mid-size storage tank, meaning it can be used to supply water for multiple faucets:

  • Flow: 75 GPD
  • Tank size: 53 gallons

  • Efficiency: 25%

  • Price: $1265

  • Rating: ★★★★★

Best RO System + Mid-Size Tank

Home Master TM

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The Home Master TM is a great compromise between a true whole-house RO systems and the cheaper under-sink models. It can be installed as a point-of-use device with a smaller tank, or supply filtered water to multiple faucets thanks to its 53-gallon tank option. This means the Home Master will provide enough daily potable water for a family of four or more.

For both filtering and softening at the entry point, we recommend the Aquasure Signature Elite Series:

  • Flow: 75 GPD / 15 GPM
  • Tank size: 3.2 gallons

  • Efficiency: 33%

  • Price: $1699

  • Rating: ★★★★☆

Runner Up Combined RO System

Aquasure Signature Elite

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For a complete whole-house filtration solution that doesn’t affect flow rate or require a large storage tank, we recommend the Aquasure Signature Elite Series. It combines three of their most well-reviewed filters.

First up is the Fortitude, which sits on the main water line and contains a carbon/KDF media to remove chemicals like chlorine and pesticides, which affect water taste and smell. Next is the Harmony, which, like the Tier 1 system, is a whole-house salt-based water softener to remove hard minerals for better showering, laundry, and scale-reduction. And finally, Aquasure’s Premier Series RO system fits neatly under the kitchen sink and provides fully-protected drinking water.

Using this Signature Elite Series setup protects your pipes and appliances, improves water quality across the whole home, and focuses the RO filtering power where it’s really needed: at the kitchen faucet.

Best Under-Sink Reverse Osmosis System

  • 🏆 Most popular under-sink reverse osmosis system: APEC Essence

If you only need filtration for your drinking and cooking water, the simplest solution is to install a standard RO filter under any appropriate sink.

These products rank among the most popular of all home filtration devices thanks to their combination of affordability, performance, and ease of installation. Even if you need two or three standard RO systems to cover every drinking faucet, the cost and ease of installation is likely to be lower than with a whole house filter.

  • Flow: 50 GPD
  • Tank size: 4 gallons

  • Efficiency: 33%

  • Price: $301

  • Rating: ★★★☆☆

Most Popular Under-Sink RO System

APEC Essence

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The APEC Essence is a contender for the most popular under-sink RO system currently available. It has scores of glowing reviews on sites like Amazon and Home Depot, thanks to its great mix of reliability and price.

With a non-acidic high output membrane and 50 gallons per day output, drinking water is delivered instantly to kitchen faucet, and won’t compromise flow rate if you choose to pair the Essence with other whole-house filtration stages. We also like the strong metal frame, which helps reduce tubing kinks, leaks, vibration, and noise.

Another option is to install a value price reverse osmosis system, like the Express Water RO5DX under every sink that’s used for drinking water:

  • Flow: 50 GPD
  • Tank size: 3.2 gallons

  • Efficiency: 33%

  • Price: $152

  • Rating: ★★★☆☆

Best Value Under-Sink RO System

Express Water RO5DX

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At around 150 dollars, it’s difficult to find a functional RO system for less than the Express Water RO5DX. Not only does it produce a respectable 50 gallons of filtered water per day (more than enough for a single faucet), it’s rated to remove all common contaminants at levels similar to the other RO systems above.

So what’s the downside to this value RO device? Well, the efficiency isn’t great, meaning you might see an increase in water consumption. There are also three carbon media stages included in this system, which we think is a little unnecessary. It means you’ll be paying to replace three different stages on a yearly basis, cutting into your savings.

  • Flow: 13.3 GPD
  • Tank size: 3.2 gallons

  • Efficiency: 17.9%

  • Price: $499

  • Rating: ★★☆☆☆

Runner Up Under-Sink RO System

Aquasana OptimH2O

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This OptimH2O RO filter from Aquasana is designed to work as a standalone under-sink filter or in conjunction with a larger whole-house system. It combines the brands’ own Claryum® media cartridges, which are excellent at targeting heavy metals, with reverse osmosis technology to remove over 80 contaminants, including fluoride, nitrates, and microorganisms.

Well Water Filtration System FAQ

Reverse Osmosis Systems – From the Blog

Even though reverse osmosis filtration systems are widely used – both in homes and at municipal treatment plants – some internet sources claim that reverse osmosis water is less healthy than regular tap water.

The reasoning behind this claim is unclear and seems to originate from several questionable articles published by websites in India. They cite the fact that RO filtration is so effective, it removes almost all dissolved materials from the water supply, including naturally occurring minerals.

This process results in a water profile that’s slightly acidic and lacking calcium and magnesium. It’s falsely claimed that these features of RO water can lead to malnutrition or gastrointestinal distress.

The truth is that even the highest mineral-content water only provides negligible amounts of these compounds, far below the average person’s daily recommended intake. Eating a regular diet is enough to ensure you’re consuming a sufficient amount of minerals.

There’s also no established advice against drinking slightly acidic water, just as there’s no advice against eating or drinking much more acidic foods like lemons or coffee. RO water tends to have a pH level of around 6.5 while normal water is approximately 7.

RO systems also effectively remove provably dangerous contaminants like lead, arsenic, microorganisms, and industrial chemicals—all of which pose a much clearer threat to health than a slightly reduced mineral intake.

If you are concerned that reverse osmosis water may reduce your mineral content, simply choose an RO system that contains a remineralization stage, such as the Aquasana OptimH2O or the iSpring RCC7AK.

These systems reintroduce calcium and magnesium salts into the water supply after filtration has occurred.

Read more on whether reverse osmosis water is bad for you in our full post.

Yes. Fluoride molecules are generally large than the pore size of most reverse osmosis membranes, meaning that they can be effectively removed from water by an RO system.

Fluoride is a naturally occurring mineral that regularly shows up in water. Most municipalities also add extra fluoride into water in an effort to help improve the dental health of the population.

As fluoride has become a more widespread ingredient in toothpaste and other dental hygiene products, many people feel that consuming water with added fluoride is unnecessary and seek to remove it.

Yes. Reverse osmosis systems will remove almost all dissolved minerals in the water supply, effectively turning hard water into soft water.

Most tap water, especially groundwater from wells, contains dissolved magnesium, calcium, iron, and other minerals. At high levels, these minerals can cause issues like scale and staining.

However, using a reverse osmosis system specifically for the task of removing minerals from water isn’t recommended, because the delicate osmosis membranes can quickly become clogged, shortening their performance lifespan.

Instead, we recommend using a traditional salt-based water softener to remove minerals. If you have hard water and also want to use an RO system, the Tier 1 Essential series provides an effective solution, combining a whole-house softener with a point-of-use RO filter.

If you’re looking for more info on how to deal with hard water, check out our review of the best water softeners.

Yes. Like other common dissolved chemicals, reverse osmosis systems are able to remove large amounts of chlorine from water.

Applying chlorinated water directly to a reverse osmosis membrane can actually degrade the quality of the material, as the chemical collects on its surface. That’s why most RO systems contain a carbon media stage to remove chlorine from the water before it reaches the membrane.

Activated carbon is a simple and effective filtration method of chlorine removal. As chlorine molecules pass through the carbon cartridge, they are attracted and adsorbed onto the surface of the filter media. When the entire surface of the carbon media is saturated with contaminants, it needs to be replaced.

Chlorine is one of the most common drinking water disinfectants, regularly used by municipal and private treatment centers to protect drinking water from bacteria and viruses.

Using a reverse osmosis system without an activated carbon stage specifically to remove chlorine isn’t recommended, as you may shorten the performance lifespan of your device.

Because they both create highly pure water that’s free of almost all contaminants, reverse osmosis and distillation are two commonly confused water treatment methods.

But while they produce similar outcomes, they are not the same.

Distilled water is created by converting water into a gaseous state and then condensing it, most commonly achieved by boiling and cooling. This process has the effect of removing dissolved solids and microorganisms from the water supply but may not remove chemicals with a similar boiling point to water itself.

Reverse osmosis water, on the other hand, is created by conditioning water using activated carbon and sediment filtration, then passing it under pressure through membranes with tiny, microscopic pores – not much bigger than water molecules themselves.

This means that reverse osmosis water should be free of minerals, metals, microorganisms, and most chemicals.

Whole House Reverse Osmosis Systems – Homeowner FAQs

Are reverse osmosis systems worth it?

There are several ways to use reverse osmosis technology in home water filtering. That means that most households can get good value from a RO system, regardless of their feed water quality.

If your water passes EPA safe standards but contains smell, taste, or appearance impurities, then an under-sink RO system is one of the most cost-efficient ways to dramatically improve water quality.

For those with unsafe private water supplies, installing a whole house RO system provides high-level filtering power that can only be matched by combining several other types of filter – which again means cost-efficient protection.

However, there are situations where a reverse osmosis filter might not be the best option for one reason or another.

If hard minerals are the main issue with your water supply, for example, a water softener is likely to be a more efficient and long-lasting solution. Likewise, those primarily looking to remove chlorine and chlorine byproducts will get more value from a simple but effective carbon filter.

What is the advantage of a reverse osmosis system?

Advantages of reverse osmosis systems revolve around cost efficiency, ease of installation, and filtration performance:

  • No other single type of home water filter can remove the same amount and diversity of contaminants as reverse osmosis systems.
  • While cartridge media stages of reverse osmosis systems may need replacing every 12 months, most RO membranes themselves should last for at least 2 years.
  • Most under-sink reverse osmosis systems can be easily DIY installed (the only issue may be fitting the faucet into the kitchen counter)
What is the disadvantage of a reverse osmosis system?

Disadvantages of a reverse osmosis system revolve around their slow flow rates, water waste, and at times excessive filtering power:

  • Because they use pressure to force water through microscopic holes, reverse osmosis systems have very slow flow rates. While other filters measure water production in gallons per minute (GPM), most RO systems are measured in gallons per day (GPD). This means that almost all reverse osmosis systems come with water storage tanks to hold pre-filtered water.
  • Another consequence of using pressure is that RO systems produce less filtered water than they take in. Most RO systems run at around 33% efficiency, meaning that they filter one gallon of water for every three.
  • Reverse osmosis filters are so powerful that they remove almost all minerals and metals from the water supply. This can result in a somewhat bland taste that some people may not like.
How long does a whole house reverse osmosis system last?

Quality reverse osmosis systems with regular maintenance should last around 20 years. The osmosis membranes themselves have a performance lifespan of 2 – 5 years depending upon their pore size and the quality and incoming pressure of feed water.

Most RO systems also contain carbon and sediment filtration stages to remove undissolved matter and organic chemicals from the water supply. These stages use replaceable media cartridges, which need to be changed every 6 months – 2 years depending upon their size and the quality of incoming water.

How much does a whole house reverse osmosis system cost?

The price of a reverse osmosis system varies dramatically depending upon whether the system is designed for point-of-entry or point-of-use applications.

Point-of-entry reverse osmosis systems tend to cost between $2,500 and $9,999. That’s because they include large water storage tanks, electrical pumps, and reverse osmosis filters capable of processing over a hundred gallons of water per day.

Point-of-use reverse osmosis systems start at around $150 and can cost up to $600 depending upon the number of filtration stages in the system. They’re generally cheaper thanks to smaller, plastic water storage tanks and capacities that max out at around 60 gallons per day.

Can I install my own reverse osmosis system?

Most people contract a professional to install a reverse osmosis system, as with other types of home filters. However, there’s nothing stopping you from installing your own system, if you have the right DIY and plumbing know-how.

When it comes to under sink RO systems, the installation of the filter itself should be relatively straightforward. The only non-DIY-friendly element is fitting the countertop faucet, which requires drilling a hole into your counter.

Whole house RO systems present a much more complex installation challenge due to their multiple large components and need for water pressure calibration. Don’t attempt to install your own whole house filtration system unless you have previous plumbing experience.

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