How Much Does a Reverse Osmosis System Cost?

The Long Version

While it may be true that there’s no price you can put on safe, clean drinking water, a whole range of aspects do affect how much you end up paying. Aside from circumstantial factors, like current water quality and typical consumption, there’s considerable variance between brands, types and specifications of reverse osmosis (RO) systems.

As RO systems are with you long-term, your initial investment is not the whole picture. While this up-front cost is not at all negligible, the efficiency of the design, and even the materials used, can be equally significant for total costs across time. 

While product descriptions and specs are mostly helpful, they can be (by design) a little bolstered or slight variations of the truth. By reading up on the subject, you can become informed on the many ways of saving money, and who doesn’t like the sound of that right? 

So let’s dive into your comprehensive buyer’s guide for the costs of a reverse osmosis system!

PRODUCT COSTS

The type of RO system is the most immediate cost factor.  Depending on your specific needs, the price of water purification fluctuates significantly. Point of entry (POE) installations, for supplying pure water to an entire household, will always be more expensive to purchase and run than under-sink units, otherwise known as point of use (POU). 

The range of products you will most typically find are:

• COUNTERTOP:  Light usage for small households supplied with municipal water

  • TYPICAL COST: $200-500

  • PROS: Low cost, simple installation

  • CONS: Lower capacity, takes counter space

• UNDER-SINK / POINT OF USE: Adequate for larger homes or particularly important faucets

  • TYPICAL COST: $400-1000

  • PROS: Powerful pressures yet remains affordable

  • CONS: Confined to a single tap, may need to install provided faucet

• COMMERCIAL: High usage for commercial spaces or substantially busy households

  • TYPICAL COST: $500-3000

  • PROS: Higher flow rates and faster refill

  • CONS: Greater rates of waste water, higher filter costs

• WHOLE HOUSE / POINT OF ENTRY: Complete system required when source water is especially contaminated

  • TYPICAL COST: $600-8000

  • PROS: Purifies all entering water

  • CONS: Expensive installation, many parts to maintain

• INDUSTRIAL: Extreme capacity for specific heavy-duty applications

  • TYPICAL COST: $15,000+

  • PROS: Highest specs available

  • CONS: Expensive, inapplicable to homes

There is great discrepancy in performance of RO systems. You may find products boasting a long list of specifications, but the most common concerns include:

Flow Rate

One of the first things to consider is system output. You’ll see this presented as gallons per day (GPD) or gallons per minute (GPM), and less commonly as gallons per hour (GPH). The quantity of pure water an RO system can produce is tied to water pressure, which can be based on several variables. 

Municipal water pressure ranges from 45 to 100 psi (3.1 to 6.9 bar), with homes in more rural areas more often experiencing lower numbers. In such a case, output is comprised. Homeowners can make use of booster pumps and pressurized tanks to increase pressure. Small pumps start at round $100, while tanks can cost as little as $50. It is important to note that in order to deliver water swiftly, RO tanks must be pressurized (hydro-pneumatic), so avoid cheaper options that lack this feature. 

The estimated daily water consumption per person is around 80-100 gallons, which includes washing and utility water. Those solely interested in drinking water may find that output loses significance after a certain point. 

It’s also important to note that a product’s GPD rating has been determined through extremely controlled conditions, where temperature and pressure were optimal. In the real world, where cold water can considerably reduce production, a 500 GPD system will most likely not achieve the exact amount.  

Output is not a hugely significant cost factor, as it is not exclusively based on the product, but the environment and existing plumbing as well. In situations where there is lower water pressures or especially high levels of contamination (for example houses on well water), homeowners should take into account the additional costs of purchasing and running an electric booster pump.

Drain Ratio

The most influential cost factor is by far efficiency, which is measured as drain ratio. Older RO systems may achieve a 1:3 drain ratio, meaning that for every gallon of pure water produced, there are 3 gallons of waste water. Modern, innovative reverse osmosis products now can reach drain ratios of 2:1, which would be 600% more efficient. 

As one would expect, the long-term cost implications of this magic number is huge. Once you’ve calculated your water usage, you can estimate the operational costs on an RO system by using the drain ratio and water unit charges. 

Assume a family has installed an under-sink RO system, from which they use 100 gallons of water per day. Their RO system holds a 1:2 drain ratio, meaning that 200 gallons of water will be rejected to satisfy this need. This results in a total of 300 gallons. In the US, water may be supplied at $0.0057 per gallon, meaning this family should expect a $50 rise in their monthly water bill. 

With countertop or POU systems, monthly water usage is very manageable. However, if you are considering a whole-house RO system, the drain ratio is massively significant to long-term cost. Point of entry systems mean that all incoming water is purified, so suboptimal efficiency can easily double or even triple water costs. 

It is also important to note that efficiency may be shown as recovery rate. A recovery rate of 50% translates to a drain ratio of 1:1, while a much more desirable 80% would equal 4:1. Many modern systems can work to these higher efficiencies, thus excessive levels of waste water – and the associated costs – should not be considered unavoidable.

Filtration stages

When it comes to the actual reverse osmosis process, various components are required. Generally speaking, you can expect an RO system to involve 2 pre-filters, the RO membrane and a final post-filter. Common filter examples include:

• Polypropylene (PP) sediment filter, which mechanically removes sand, dirt and rust particles

• Carbon block (CB) filter, a solid block of compressed carbon that is effective at absorbing numerous contaminants

• Composite filter (CF), a combination of PP cotton layers with an activated carbon section. These filters achieve the same results as their constituents, yet are presented as a single filter

• Granular activated carbon (GAC) filter, typically made from organic materials like coconut shell or charcoal that are suitable for dechlorinating water, as well as removing unpleasant odors

Product pages are quick to let you know about filtration stages. A basic countertop model may be 4-stage, while more sophisticated designs can involve as many as 10. However, filters often contain numerous films or sheets. An 8 filtration stages rarely means there are 8 individual filters at play, but rather 2 or 3 multi-layered filters alongside the RO membrane.

The more filters your system has, the more replacements you will be required to make. The membrane lifespan is also drastically reduced when pre-filters are not used or replaced regularly. Pre-filters don’t just benefit the purity of the water, but also preserve the more expensive (and essential) RO membrane by reducing strain.  The costs of filters are covered in the maintenance section.

NSF certifications

National Sanitation Foundation (NSF) food safety and sanitation standards are not a given with RO systems. When the manufacturer is able to show a rating, it’s a reflection of superior materials and extensive testing. 

While the NSF covers a spectrum of food and drink certifications, those specifically relate to water filtration are:

• NSF42 (Aesthetic Effects): Reduction of chlorine, chloramine, iron, manganese, zinc (among others) and the reduction of bad taste and odor

• NSF53 (Health Effects): The reduction of over 50 contaminants, the most popular including lead, Cryptosporidium, VOCs and chromium

• NSF401 (Incidental Contaminants): reduction of specific compounds, including prescription drugs, over-the-counter medications, herbicides, pesticides and chemical compounds

While NSF-certified products may carry a higher initial cost, they should last longer than cheaper alternatives, thanks to more stringent build standards. NSF ratings suggest that the product is less likely to leak or leech contaminants back into the water.

These health certifications are evidence of a more reliable system, which should be taken into account when considering purchase price against future maintenance costs.

Tank vs Tankless

You may decide to install an RO water tank to increase the flow rate, particularly if you have suboptimal water pressure or brief periods of very high usage. Having a water tank allows users to store their purified water, though doing so for too long may cause the freshness to spoil. 

Assuming you are using a water tank without a pump, you do not require power. Consequently, you won’t need to worry about extra utility cost. Typically two to four gallons in size, these containers tend to follow dimensions of 15” x 12”, or 38.1 x 30.5cm, which makes installation simple. Most under-sink areas will have adequate room for such a tank. 

As for cost, RO pressurized water tanks are relatively inexpensive. You will be able to source one for as little as $50, and you can still expect good competition at that price point. Counterintuitively, RO systems with tanks are more affordable than tankless alternatives. 

Although tankless models are more expensive, they usually produce less waste water than tanked equivalents. Over a considerable time, the cumulative savings on water charges will be significant. At the same time, tankless RO systems require electricity, so you may not find much difference in long-term running costs.

Cost-saving features

Many manufacturers find ways of increasing efficiency in order to reduce long-term operation costs, which may involve the use of smart technology.

AUTO SHUT-OFF VALVE (SOV): If you accidentally leave a faucet running, this feature will shut off the water supply to limit wasted water. Only a small amount of pressure, created by the float valve, is needed for these valves to operate. Users can actually add this functionality to standard under-sink systems for minimal expense. 

AUTO FLUSHING: In order to prevent scaling of the membrane, an RO system needs to be flushed periodically. Many products will incorporate a manual flush valve, but you may also find electronic auto-flush capability. As this rapid rinsing removes impurities and preserves the membrane, having it automated can improve product lifespan. 

RECYCLE VALVE: An RO system uses a recycle valve to significantly improve efficiency. Such a feature means that when the concentrate water is passed through the system, it can be reintroduced rather than simply dumped. Recycle valves are not standard on cheaper models, though they often crop up on whole-house systems.

MAINTENANCE COSTS

When considering the cost of an RO system, one must keep extended maintenance in mind.

Filter lifespan and replacement costs

Whilst easy-twist filter replacement or reusable cartridges are convenient, people are more concerned with how frequently they must swap out their filters. 

Generally, manufacturers recommend that pre and post-filters be replaced every 6 to 12 months, while RO membranes can last between 12 and 36 months. Anecdotal evidence suggests that especially attentive owners can maintain a single membrane for as many as 8 years. 

How often you should change filters depends on the quality of the pretreated water, which may be measured in total dissolved solids (TDS). Excessively hard water will prove more taxing for the system. How much water is consumed is also significant, as households getting through larger quantities will find themselves replacing filters faster. 

Domestic costs of a POU system can range from $60 to $200 annually. If we assume that you are replacing 2 pre-filters and 1 post-filter a year, as well as the RO membrane every 2 years, it’s most likely you’ll spend around $120. For whole-house units, or indeed commercial, you can anticipate the much higher maintenance costs between $250 and $1000. 

Some companies prefer to use reusable housing. In this case, you can save some money by not needing to repurchase filter casings. Modular designs, on the other hand, carry extra costs as they must be wholly replaced. Luxury products may have proportionally expensive filters, so it may be useful to visit the appropriate websites in order to estimate annual costs. 

Reverse osmosis systems with lower price tags, namely countertop models, have correspondingly affordable maintenance costs. Their basic design means fewer components, leaving you tasked with changing out just pre-filter and membrane.

Product Materials

MEMBRANE MATERIAL: The RO membrane is the beating heart of the system, so it’s important to ensure the product you choose makes use of superior materials. There are two common types of membrane, Thin Film Composite (TFC) and Cellulose Triacetate (CTA). 

Cheaper products may be hiding a CTA membrane. With an average lifespan between 18 and 24 months, it can be considered inferior to TFC membranes, which can last for up to 8 years when properly maintained. When it comes to water quality, TFC achieves higher levels of purity, eliminating 98% of contaminates as opposed to 93% with CTA.

PLASTIC vs METAL: RO systems are predominantly plastic, which is both cheap and effective. As many are made from BPA-free materials, there is little chance contaminants will leech into the water. In any case, look for the aforementioned NSF certifications if you’re worried about this kind of pollution. 

You may find models with stainless steel housing, though the price does not seem to alter significantly. There is virtually zero difference regarding water quality, so it’s simply a matter of individual taste.

Trusted brands and performance

As with anything, finding a reliable brand you can trust massively influences overall experience, not just initially but in the long run as well. While an experienced and trusted manufacturer makes a better product, it also means you can easily source replacement parts, including filters, for years to come. 

Providers of the cheapest RO systems are not necessarily concerned with long-term customer experience. While you may save money initially, it may quickly prove difficult to find compatible filters or get in touch with customer service. 

In no particular order, here are some trusted providers of RO products:

• Waterdrop

• iSpring

• Purlette

• NU Aqua

• WECO

• Crystal Quest

There are many more names with loyal customer bases. A brief search through reviews will give you an indication of product quality, as well as whether or not the company has a good rapport with its users.

INSTALLATION COSTS

While countertop RO products simply plug in, more powerful units must be installed into the existing plumbing. The more complicated your system, the higher the cost of parts and labor, with point of entry (POE) installations potentially costing thousands.

DIY or technician?

An under-sink, or point of use (POU) reverse osmosis system can be installed with minimal tools. Even with limited experience, there’s a good chance you’ll be able to do it yourself. You should set aside one or two hours in order to:

• Mount supply feed and attach faucet

• Install drain saddle

• Fasten the RO unit

• Connect to water feed

• Mount pressurized tank

• Install filters and membrane

• Start system and check

Providing you’ve got a screwdriver, adjustable wrench and utility knife, you’ll be able to complete the installation, saving yourself a great deal of money.

Cost of labor

If you do go down the professional route, you may pay anywhere from $100 to $500 and if your set-up ends up being a little more complicated, there may be extra costs. The additional parts and tubing for a whole-house installation means labor costs can go well above $1,000.

Cost of parts and supplies

Your system should come with the required fastenings included. In certain situations, you may need additional connectors and fittings, but the costs for these are negligible. Costs may begin to rise when larger, sophisticated units call for specialist parts.

COSTS vs VALUE

Anticipated savings

In many US locations, municipal water is supplied at $0.0057 per gallon. Conversely, the average price for a gallon of bottled water sits at $1.18. This means that bottled water is an eye-watering 200 times more expensive than tap. 

Assuming that an individual drinks 0.5 gallons of bottled water per day, a household of four will get through 2 gallons every day. Yearly expense would be 730 gallons x $1.18, or $861.40. 

That same family using an RO system, with a 1:3 drain ratio, would get through 4 times as much water, meaning yearly expense would be 2920 gallons x $0.0057, or $16.64. 

Add your $80 yearly maintenance cost for an estimated total of $96.64 annually. Even if your RO system cost $500 and was professionally installed for $200, you would still save money in the first year if you had relied exclusively on bottled water beforehand. 

Costlier systems and installations will still even out quickly, between 2-5 years. The more water consumed, the more money is saved, so the time it will take you to get back into the black will vary. Serious savings can be made quickly in commercial settings, though even busy households can expect huge improvement by swapping out bottled water.

Is it worth it?

While a reverse osmosis system may not suit all circumstances, it’s a safe and reliable method of purifying water. The decision to invest in RO technology is usually out of necessity, where water is unpleasant or a risk to health. 

These systems eliminate 99% of over 1,000 contaminants and certain impurities, such as nitrates and arsenic, are extremely challenging to remove through other purification methods.  

Consider purchasing a test kit to assess the current condition of your water. If you discover considerable contamination, you may feel investing in an RO system to be a no-brainer. After all, there’s no price on good health. 

If cost is the most important factor, the type of RO unit you choose can make the decision easier. If you are supplied with potable water, which is fine to use in the shower or dishwasher, you can limit initial costs by sticking to a single point of use (POU) system just for drinking water. 

At the end of the day, only you will know whether the value of pure and pristine water on tap merits the associated costs of purchasing and maintaining your very own RO filtration system.