Looking for an affordable reverse osmosis system in Seattle, WA? Great! Mr. Blue Plumbing is at your service 24/7.

In this guide, we cover common questions including:

  • How Much Does Reverse Osmosis System Installation Cost In Seattle?
  • What Are The Common Water Contaminants In Seattle That Reverse Osmosis Can Fix?
Reverse Osmosis Systems Seattle, WA

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Seattle, WA


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Area Served: Seattle, WA


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How Much Does Reverse Osmosis Installation Usually Cost in Seattle?

As the largest city in Washington and the Pacific Northwest, Seattle is truly a spectacular place. It is the birthplace of Boeing, Microsoft, and Amazon. Most people appreciate it for its well-known and loved scenic views of the Puget Sound and the iconic Space Needle. Indeed, there are numerous reasons to visit.

Beyond that, it is also a great place to call home, as proven by the more than 724,000 people who live here. It has been this way throughout history since its founding in 1851. Once a timber town, it was a useful land for those seeking natural and mineral resources. The Klondike Gold Rush ended the depression in Seattle.

With all its history, minerals, and resources, we have to wonder about the water quality of this great city. Surprisingly, Seattle has relatively soft water. On average, the water hardness scale goes from 12 PPM to 218-PPM, with 12 being the softest water available. Seattle’s water supply comes in at 22 PPM. However, this doesn’t mean you may not sometimes want to treat your own water before using it in your home, which was proven in December 2020 when untreated water leaked into the treated water supply. However, this is also where things get a little confusing. How do you treat water? The easiest way is through reverse osmosis.

When talking about reverse osmosis (RO), there are a lot of things to consider. One of the biggest for most families is the cost. Unfortunately, there is no easy way to predict how much it will cost to install this system. 

For a reverse osmosis system, you can expect to pay between $200.00 and $5,000.00 depending on several factors and what you need for your home. The average homeowner will typically pay around $2,000.00. However, your situation, your needs, and other factors may increase or decrease your out-of-pocket cost. 


Labor and plumbing costs for a reverse osmosis machine will vary. It mainly depends on the complexity of your system and the setup required for it. On average, some plumbers will charge between $45.00 and $200.00 for their time. You may also have to spend more money if you need the system installed on short notice.

System Size

A reverse osmosis system is rated based on the Gallons Per Day (GPD) that they can produce. It indicates the filter pore size and how long it may take water to be pushed through. On average, for most homes, a minimum of 50 GPD is recommended. You should choose to go higher in Seattle because of the cold weather, which can reduce water production rates.

As with all other plumbing requirements, the larger system you need for your home, the more expensive it may be to install. 

Your Needs

For some people, a simple under-the-sink setup or pitcher is enough. For others, they want to know that the contaminants are eliminated from their entire home’s water supply.

On average, you should choose a reverse osmosis system that can supply 1.5 to 2 gallons per day for each adult and 1-gallon per child. This means if you have a family of four, 50 gallons should be enough, but in a home where there are seven people, you may want to opt for something closer to 75 GPD.

What Are the Most Common Water Contaminants in Seattle?

Water, no matter where you live, is always at risk for contaminants. Most of our water supply comes from natural sources, including rainwater and ground runoff to the nearest lake or water aquifers. Seattle is no exception. Its main water supply is from two nearby rivers – The Cedar River, which is 35-miles southeast of Seattle, or the Tolt River Supply, located in East King County. Both provide water to nearly 1.4 million people and also offer a home to wildlife and salmon. This does mean that contaminants are possible, but Seattle does its part to ensure it is right before it gets to your home. 

In Seattle, the water supply does have some contaminants. There may be:

  • Microbial Contaminants: This includes some viruses, bacteria, and protozoa. These things are found in all soil because they come from the wildlife around every part of the world.
  • Inorganic Contaminants: You will find this in all soil because it comes from metal deposits and salt.
  • Organic Contaminants: This is mostly chlorine that comes naturally from the environment. However, there are other types of chlorine and in the water that stems from how your drinking water is disinfected.

These are things that are unavoidable in every water source throughout the world. The good news is, overall, Seattle does still have impressive water quality by all standards. However, some people may be more negatively impacted by the contaminants that are in the water. Therefore, many people do opt to have a reverse osmosis system installed.

Can Residents in Seattle Benefit From Reverse Osmosis Treatment?

The reverse osmosis system is designed to remove even the tiniest contaminants from your water supply. In fact, most reports say that it can remove up to 99% of them. If you have stains in your tub or feel that there are minerals in your water supply causing you problems, reverse osmosis is a good option. 

There is a downside, though. You have to be prepared to lose even the good stuff that is in your average water supply. According to some studies, you may get valuable nutrients from the water. Removing them could mean that you must be willing to use supplements or find other sources of those nutrients. For most people, this should not be a concern. The benefits of a reverse osmosis system may by far outweigh the risks. You will have to decide for yourself which you prefer. 

How Often Should Residents in Seattle Replace Reverse Osmosis Prefilters?

As with most filters, the more you use it, the faster it may clog and restrict the flow of water that can go into your home or business. In general, it is recommended that you change out your pre-filter every year. However, if you have a high chlorine concentration in your water, changing it every six months may be best. 

Considering Seattle’s water supply is frequently going to have chlorine from the treatment facilities, this can be a problem that requires you to change out your filters more often. You should also change it out in situations where groundwater contaminates treated water, as occurred in 2020. Groundwater contaminants can be at a higher level until the city gets it back under control, which could also mean that even more chlorine is added to the water supply to try and correct the problems.

However, it may also depend on your system. There may be different types of flow configurations on your system. It could be a single-stage, two-stage, single-pass, or two-pass system. 

The two-pass system is the most common. They treat water in the most effective way possible, but it could also mean you have to change filters more or less often than with some others. 

We urge you to check the recommendations for your particular unit to avoid unnecessary risks and problems for your system. If you are uncertain of the type of system you have installed, you can always ask for help to handle filter changes. 

Do You Need a Water Softener With Your Reverse Osmosis System in Seattle?

As proven, Seattle has high-quality water that usually tests very well. They meet or exceed most standards for quality, and there is very little water hardness coming from the water treatment facilities. 

However, if you have old pipes in your home, you could still have contaminants residing there. The same is true if you have a private well rather than city water. The contaminants you may find are most often:

  • Microorganisms: Human sewage and animal waste can both be found everywhere. It seeps into the ground with every rainfall and can show up in your home’s water supply.
  • Heavy Metals: Every pipe in the ground can contaminate your water supply, especially if your pipes are older.
  • Nitrate or Nitrite: Chemical fertilizers, sewage, and waste fill our land surface. These things also contribute to nitrates in the water supply, which can cause health concerns later on.
  • Organic Chemicals: Considering Seattle’s past as a timber town, it should not surprise you to know that there could be organic chemicals from pesticides, disinfectants, and other agricultural and industrial contaminants in groundwater. In most cases, you shouldn’t have to worry about an excessive amount, but organic chemicals can cause kidney damage and other issues in some situations.

This is not a complete list of the potential chemicals in your well water. For that, you would need to have your private well tested. 

With that in mind, you should consider running both a water softening system and a reverse osmosis system, especially if you are using a private well that isn’t constantly monitored to ensure quality. They do different jobs, and a water softening system may actually extend the life of your reverse osmosis unit.

A water softener uses sodium chloride or potassium chloride to reduce water hardness, taking out calcium and magnesium that can be picked up as it travels through water lines and into your home. It may also work well to remove radium and barium.

This is good news for your reverse osmosis system, which uses fragile membranes to filter your water before drinking it. Most of these systems struggle to remove calcium and magnesium.

If you have both installed, it can even allow you to have a smaller reverse osmosis system on your home’s water supply. When the two are paired together, many homeowners opt just to install an under-the-sink reverse osmosis unit to cut down on the cost while ensuring that your kitchen tap water is as healthy as possible.

Recent Requests We Received From Customers In Seattle, WA

Date of Request: May 30, 2023

Location: Seattle, WA


Quote for Single faucet RO System for our kitchen.

Date of Request: June 1, 2023

Location: Seattle, WA


Need to install under sink reverse osmosis filter.

Date of Request: May 29, 2023

Location: Seattle, WA


Reverse osmosis drinking water system. Thanks!

Date of Request: May 29, 2023

Location: Seattle, WA


Reverse osmosis water filter.

Date of Request: May 29, 2023

Location: Seattle, WA


RO Drinking water system.

Date of Request: May 29, 2023

Location: Seattle, WA


Whole house filtration.

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