A lot of homes across the US have to deal with the problem of hard water, and a water treatment system is the most obvious solution to the problem. Among the different types of systems used, reverse osmosis systems, or RO systems, are among the most popular choices. We’re going to take you through the cost of RO water treatment systems, factors that affect that cost, the type of RO systems, and maintenance costs.

What do home RO systems cost?

reverse osmosis

What a RO system costs depend on a variety of factors, including the type of system, size, the brand you choose, the lifespan of the filter, and more. 

For example, a POU (point of use) system will cost you less than a point of entry (POE) system. A tankless system is more expensive than a system with a tank. Let’s discuss the different types of reverse osmosis systems and what each of them cost.

Types of RO water filters

Point of use (POU) systems

As the name suggests, these water filtration systems are designed to purify the water at a particular source point, such as a sink, for example. These are most commonly used to provide drinking water, reducing the need to spend on bottled water. Let’s take a look at three types of POU reverse osmosis systems.

Countertop RO system

These are portable RO water filters that do not need to be connected to any water source. The ease of operation, thanks to the minimal setup required, makes them a popular choice. The average cost of a countertop system is between $300 and $500.

Under sink with tank

These are the traditional RO filter systems that come with a storage tank for drinking water under the sink. The average cost of this type of RO system is between $200 and $600. 

It is worth noting though that you can buy a high-quality system even at the lower end of the price spectrum with these models. The biggest downside to these systems is that it may take a couple of hours for the tanks to fill up.

Tankless under sink

This is what you ought to buy if you want an RO system that gives you clean drinking water on demand. These systems are under-sink reverse osmosis systems designed to filter water instantaneously, and are slightly more expensive than the with-tank systems, costing between $200 and $600 on average.

Point of entry (POE) systems

reverse osmosis types

Point-of-entry RO filtration systems are also known as whole-house RO systems. A house RO is much more expensive than a POU RO system. Depending on the capacity of the system, its size, and whether you choose any extra features with it, expect to pay between $1,500 and $10,000.

However, these systems effectively remove chlorine and affluence from the water, giving you soft and potable water throughout the house. You can buy POE systems for both domestic and for commercial deployment.

Factors that affect the cost

Now that we know what the average cost of different home reverse osmosis systems is, let’s try and get a better understanding of the factors that affect the cost of these systems.


It should come as no that size affects the cost of these systems. The larger the system, the more expensive it will be. For example, any POE system will cost more than a POU system.

System type

An under-sink system with a tank is the most affordable of these systems, with tankless and countertop systems costing around the same.

Larger, more complex whole-house systems cost thousands of dollars. One of the reasons manufacturers can charge those rates is that there aren’t too many competing brands in the segment.


RO water wastage is a constant irrespective of which type of RO system you use. However, more efficient systems will waste less water and will, therefore, cost you more.

A traditional RO filtration system has a wastage ratio of 1:4, which means for every gallon of water purified, four gallons are wasted. However, newer systems are a lot more efficient, with ratios of 1:2 or even 1:1. Obviously, these more efficient systems will cost more.

Another efficiency parameter that is taken into consideration is how fast these systems can purify water. The faster the purification, the more expensive the system will likely be.

Filtration stages

All RO systems are meant to give you high-quality, soft potable water. There are a number of filtration stages that the water goes through. Systems that have more than the regular number of filtration stages cost more.

The average RO filtration system has 4 stages: a pre-sediment filter, a carbon filter, a semipermeable membrane filter, and a post-filter. A system like this guarantees the removal of 99.9% of total dissolved solids (TDS) from the water.

However, some POU and POE systems feature more than 10 or 12 stages, such as extra carbon block filters, GAC filters, and alkaline or mineral filters. This means the water you get is as pure and clean as possible.

However, the more stages, the more expensive the system itself will be, as will maintenance and replacement as well. So make sure the extra cash you’re going to spend on the extra filters is actually necessary and worth it.


The brand you choose also has an impact on the cost of the system. A reputed and tested brand will have a lot more reviews, is more reliable, and will cost you more.

On the other hand, while a new manufacturer may not have the data necessary to guarantee the quality of the system, you are likely to get a much better price on the product.


The national standard for RO systems, which indicates that the system has been tested for structural integrity, efficiency, and removal of contaminants, has quality materials used, and has passed the test, is the NSF/ANSI 58.

All top brands are bound to have this certification.  Some brands may claim to have been tested for NSF certification, but that is not the same as being certified. Certified brands may cost you more, but you have surety about the quality of the product you are investing in. 

Add ons

There are several add-ons you could choose for your RO system, and the more you add on, the more you will end up spending. These add-ons include additional water softeners, UV lamps, remineralization filters, and booster pumps. 

A lot of these add-ons actually do help. For example, if you live in a home with poor water pressure, the booster pump is a necessity. If you think your water supply may have pathogens, the UV lights give you much-needed protection. And if you want essential minerals in your water after it has been purified, add on a remineralization filter.

Maintenance and operational costs

plumber with reverse osmosis

Let’s take a look at some of the maintenance and operational costs you will incur other than buying and installing the RO system.

Filter and membrane replacement

The carbon filter, post filter, sediment filter as well as semi-permeable membrane in your reverse osmosis system will need to be changed. How often they will need to be changed will vary depending on the manufacturer, so make sure you check your owner’s manual and adhere to the schedule advised by the manufacturer.

If you fail to periodically replace these components, your RO system will not function properly. There are two problems that could arise. One, your filters could get so clogged with sediments that you will have poor water pressure. Or your filter membranes could tear, which would mean nothing gets filtered through the system.

On average, most manufacturers advise you to change the RO membrane once every two years, and the filters every 6 months to 1 year. Filter cartridges come in packs of three, and will cost you between $30 and $50. Membranes cost around $30 to $70 each.


This is a cost that you cannot avoid if you have an RO system. However, wastewater will not add a significant amount to your bill if you’re only using a POU system. Whole house systems waste the maximum amount of water.


The whole house reverse osmosis systems and under snk systems do not use electricity to function, since they depend more on water pressure to send the water through the filtration stages. However, 

countertop systems do need electricity to function, even though most of them use less power than a standard light bulb does.

If you need a pressure pump, that is also something that requires electricity to function.

Read more: Common plumbing issues

Are reverse osmosis water filtration systems worth it?

We’ve worked out the costs and benefits of investing in these systems. So are they worth the money?

If you invest in a decent RO system, you are likely to save hundreds of dollars every year on packaged drinking water alone. The average RO system will serve you for at least 10 years, if not more, so you can more than recover your upfront investment by then. Keep in mind that if you stick to a healthy maintenance schedule, you will spend less than $900 over those 10 years on spares. That does not sound like a bad deal at all, does it?

Reverse osmosis system costs, types and maintenance was last modified: August 10th, 2023 by Narayan Shrouthy
Your opinion matters, leave a comment
Inline Feedbacks
View all comments