Reverse osmosis is a complex process whereby minerals and salts are removed from natural water by forcing it through a semipermeable membrane under high pressure.

Reverse Osmosis System Cost

This process removes most of the impurities like salts and minerals, thereby making it almost 100% pure. The processes to achieve this can vary on cost, depending on whether the system will be installed in a commercial or domestic setting

The average cost of an industrial reverse water osmosis system is $1500, whereas a simple domestic reverse osmosis filtration system will average around $500.

RO System TypeAverage Price Range
Basic Domestic Systems$150 – $499
Under Sink Systems Tankless$299 – $750
Under Sink Systems w/Tank$175 – $650
Whole-House RO Systems$1250 – $10k +

But as more people are coming to realize that water is an ever more valuable commodity, it is important to note all the costs involved by adding an RO system to your home or business. This is what I’ll cover below.

RO Countertop (Domestic) Costs

All reverse osmosis systems require two things: water pressure and water temperature. The quality of both will affect the quality of the RO water output at the end of the process.

For a basic domestic reverse osmosis system cost, you will be looking at a range of $150-$499. This will comprise either an under-counter or countertop unit that connects to a single faucet, most likely in the kitchen sink.

However, these are unlikely to have National Sanitation Foundations (NSF) certification, and the quality of the RO treated water cannot be determined. The cost of NSF certification (1) will add considerably to the overall cost.

Cost Factors For a Reverse Osmosis System

Another factor impacting reverse osmosis system cost is the refinement of the filtration process. Filtration requires semipermeable membranes usually made of some polymer material which are less costly than those made of ceramic or metal. 

The first stage of filtration usually comprises the water being passed through carbon cartridges, which remove chlorine and sediment particles. The water is then forced through a semipermeable membrane under high pressure, in a process opposite to osmosis. Osmosis is the process of a e.g., a solution of salt in water moving through a semipermeable membrane e.g., a cell wall, from a lower to a higher concentration until both concentrations are equal. 

This forcing water through a semipermeable membrane under high pressure removes salts and minerals such as sodium, fluoride, lead, copper, arsenic, and others.

The water is then processed through carbon a second time to “polish” it.

Lower water pressure may mean that a booster pump will be required to bring the water pressure up to a level where the reverse osmosis process can be implemented.

Water pressure needs to be a minimum of 50 psi (2) (pounds per square inch) for a reverse osmosis system to function effectively. If not, your wastewater volume will be higher, the filtration process will not be as effective and the whole process will generally not be optimal. A booster pump will add to the reverse osmosis system cost.

You may require an additional stage whereby minerals are added back to the water to make it more palatable. RO water is acidic, making it bitter. Alkaline water with a pH of 7 or higher is much better on the palate.

To summarize, the cost factors of a domestic reverse osmosis system include, and will vary according to:

  • Water pressure
  • Water temperature
  • NSF certification
  • Degree of filtration required
  • Remineralization
  • Additional equipment

You can expect to pay between $150-$600 for a single-point domestic RO system

Whole House Reverse Osmosis Cost

You may wish to consider having your entire home kitted out for reverse osmosis, however having this installed in a new build is an easier and more cost-effective option. This is known as a Point of Entry (POE) system, as opposed to a Point of Use (POU) system, which would be a single outlet such as a kitchen or shower faucet.

How much water needs to be purified daily and how refined you want the end product will substantially affect the cost.

Factors that need to be considered for a whole house reverse osmosis system include:

  • The RO system filters – carbon and semipermeable membranes
  • You may need a water softener if the pH level is above 8.5
  • Storage tanks
  • Distribution system,(3) i.e., pipes, valves, and hydrants

Costs may vary from around $500 to $10 000, depending on the sophistication of the system, but the average cost (4)will be around $1500.00 for a whole house RO system.

Commercial Reverse Osmosis System Cost

An industrial or reverse osmosis system cost may run as high as $20,000.00 or more. A commercial reverse osmosis system would require:

  • Initial carbon filtering
  • Anti scaling
  • An atmospheric tank, i.e., a tank that holds the contents at ambient pressure
  • Pressure and distribution pumps
  • A UV disinfection process
  • Secondary carbon filtering

To summarize:

  1. A domestic single outlet reverse osmosis system cost could be approximately $150.00.
  2. A whole house reverse osmosis system cost could be approximately $1500.00.
  3. A commercial reverse osmosis system cost could be approximately $20 000.00.

Reverse Osmosis Filter Cost by Brands

The cost of RO filters can vary by brand. We look at the following:

Culligan RO System Costs

The Culligan US2 2Stage Drink WTR System filters water for a better, safer  taste for cooking and drinking

It removes minerals and chemicals including chlorine, atrazine, cyst, lead, lindane, as well as turbidity and nominal particulate Class 1 (0.5 – 1 micron). 

This system includes an easy change filter with no need to turn off your water supply. The LED display will advise you when the filters require changing.

This item retails for $106.54 on Amazon.

Pro+Aqua Elite RO System Costs

The Pro+Aqua Whole House Water Filter 3 Stage Well Water Filtration System will remove up to 99% chlorine and dissolved metals including lead, mercury, nickel, and chromium. It will also clear turbidity caused by rust, sand, and fungi. Minerals such as aluminum and copper will also be removed.

This whole house unit retails for $375.00 on Amazon

ISpring RO System Costs

The RCC7AK 6-Stage Under Sink Reverse Osmosis Drinking Water Filter System is NSF certified and will remove up to 99% of contaminants including chlorine, fluoride, lead, arsenic, asbestos, calcium, sodium, and hundreds of others up to 0.0001 microns.

The sixth stage is an Alkaline Remineralization filter which replaces healthy minerals to restore the water to an equitable pH level of 7 or less.

The system retails for $199.00 on Amazon

EcoPure RO System Costs

The EcoPure Purifier Under Sink Replacement Water Set comprises filters that eliminate 99% of bacteria, viruses, and cysts. The unit is NSF certified to reduce contaminants including lead, chemicals, sediment, and chlorine.

The filters have an auto shut-off mechanism when they need replacing, which prevents contaminants from permeating the membrane.

The system retails for $102.93 on Amazon.

Home Master RO System Costs

The Home Master Artesian Full Contact Under Sink Reverse Osmosis Water Filter System comprises 7 filtration stages.

It removes 99% of chlorine, chloramine, lead, and fluoride as well as other heavy metals and chemicals, It is NSF certified and requires filter changes once a year or after every 2000 gallons processed.

Calcium and magnesium are added twice during the process to restore taste and pH levels.

The unit retails for $373.56 on Amazon.

Express Water RO System Costs

The Express Water Reverse Osmosis Water Filtration System has 11 filtration stages. It removes up to 99% of contaminants including lead, chlorine, fluoride, calcium, and arsenic as well as nitrates and bacteria.

It uses a UV sterilization system to eliminate E-coli, viruses, and other microorganisms. Minerals such as calcium, potassium, and magnesium are added back to the water to restore the pH balance. 

It retails for $259.99 on Amazon.

Aquasana RO System Costs

The Aquasana OptimH2O Reverse Osmosis Under Sink Water Filtration System filters 95% fluoride, 978% chlorine, and 99% other contaminants such as lead, mercury, asbestos, and other chemicals. 

This is the first system to combine reverse osmosis, claryum filtration which reduces 15x more contaminants,  and remineralization.

The unit retails for $399.99 on Amazon.

Brondell RO System Costs

The Brondell Circle Reverse Osmosis Under Sink System is a 4-stage filtration system. It uses patented technology to eliminate backpressure, which enables a 6l tank to refill in less than an hour.

The four filters are separated which assist in reducing harmful minerals and chemicals. 

The system is Gold Seal Certified by the Water Quality Association. 

It retails for $239.99 on Amazon.

Whirlpool RO System Costs

The Whirlpool WHER25 Reverse Osmosis Filtration System reduces chlorine, lead, chemicals, and dissolved solids to eliminate odor.

The 3-stage system needs fewer filter changes and uses long-lasting membranes.

The unit retails for $157.52 on Amazon.

To summarize:

CulliganUS2 2Stage Drink WTR System$106.54
Pro+Aqua EliteWhole House Water Filter 3 Stage Well Water Filtration System$375.00
ISpringRCC7AK 6-Stage Under Sink Reverse Osmosis Drinking Water Filter System$199.00
EcoPurePurifier Under Sink Replacement Water Set$102.93
Home MasterArtesian Full Contact Under Sink Reverse Osmosis Water Filter System$373.56
Express WaterReverse Osmosis Water Filtration System$259.99
AquasanaOptimH2O Reverse Osmosis Under SInk Water Filtration System$399.99
BrondellCircle Reverse Osmosis Under Sink System$239.99
WhirlpoolWHER25 Reverse Osmosis Filtration System$157.52

Reverse Osmosis Operating costs

Filter replacements

Depending on their quality, filters should be replaced once or twice a year. Reverse osmosis semipermeable membranes will probably need replacing every 3-5 years. The more filter stages the membranes have, the higher the cost.

However, more membranes also translate to less water wastage.

The filters need to be changed as they will begin to clog up with the debris they are sifting. If the filters are not changed regularly, they will eventually lose their effectiveness; the salts and minerals that you want removed from the water will stay in place. 

If the water starts to taste strange even within six or twelve months, it’s advisable, to begin with changing the filter to see if that improves it. 

Although it is entirely possible to change the filters yourself, it may be a good idea to get a professional in to do the work. If they are not an absolute correct fit, they will simply allow contaminants to pass around rather than be stopped by the filter.

Professionals will also have a knowledge of a variety of brands and be able to ensure that the correct make is fitted to your system.

Reverse osmosis System Wastewater

Reverse osmosis wastes a huge amount of water, so you can expect your water and sewerage bills to increase.

Remember that your water pressure will affect how efficiently your RO system works. The lower the pressure, the harder the RO system will have to work and the less productive it will be. 

With older systems, it generally takes about 4 gallons of water to make one gallon of RO water (5). The wasted water can be recycled, but bear in mind that it still contains impurities.

More moderns systems have refined that by half, i.e., only two gallons of water are wasted for every gallon of pure water produced.

A pressure pump and a recycle valve can improve this even further, by losing only one gallon of impure water for every three gallons of filtered water produced.

Why does RO cost so much?

The high costs of energy used to run the process as well as the ratio of wasted water to usable water push up the costs of reverse osmosis.

How much power does the RO process require?

Reverse osmosis uses electrical energy, about 3 – 3.5 kWh/m3, (approximately three kilowatt-hours per cubic meter). This is inconsequential in a domestic setting, but the sheer volume in a commercial environment is different. 

Is it worth buying a new RO water purifier?

Water that has been treated by reverse osmosis is considered to be essential by many people. Others say that the drawbacks of removing all the beneficial salts and minerals as well as the bad, make it an unhealthy choice.

So, the decision of whether to buy a new RO purifier will depend on your point of view.


We have seen that the cost of a reverse osmosis system differs widely according to the environment in which it is installed. Costs can vary from around $100 for a basic at-home under counter system to many thousand for a complex commercial enterprise.

Many factors have to be considered when deciding whether reverse osmosis water is good for you: 

  • Whether you prefer pure water that has approximately 99% of impurities removed
  • Whether the removal of those impurities along with all the good elements is beneficial to your health
  • whether the cost of a reverse osmosis system as opposed to other methods like distillation or bottled water is worth it.

In the end, it boils down to a personal decision.


  1. NSF FAQ Jan 12 Final.pdf

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