Can Whole House Water Filters Cause a Pressure Drop?

Author: Jason Hollow - Published: 2021/09/15 - Updated: 2022/11/08

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Whole house water filters are practical appliances that remove contaminants and excess minerals from water, making it safer for you and your home.

However, besides having an unlimited supply of clean and filtered water, it’s also essential to have adequate water pressure around the house. If either of the two is missing, a whole house water filter will pretty much be a miserable investment.

This brings us to the fact that all filtration systems restrict the flow of water, which ultimately causes a pressure drop. The good news is, this drop in water pressure usually is neither significant nor problematic.

If you don’t have the foggiest idea about how whole house water filters or other elements that may affect your water pressure, you are at the right place. Stay with us as we highlight the most common mistakes to avoid pressure drops around the house, at the same time, ensure clean filtered water 24/7.

So, here is our guide on whole house water filter pressure drops!


  • The use of a whole house water filter restricts water flow and may result in a significant decrease in water pressure.
  • The decrease in pressure should ideally not exceed 2 to 3 psi.
  • Pressure may be impacted further if your system is too small or clogged.

What is Water Pressure and Water Flow Rate?

Before moving onto the impact of whole house water filters on water pressure and water flow rate, it’s essential to differentiate between the two. Water flow rate and water pressure are like two sides of a coin. They’re similar, but not entirely the same.

To simplify, water flow refers to the quantity of water that flows at a given time. On the other hand, water pressure measures the force, or the speed, at which it flows.

You see, to help your water flow from the city reservoirs through the distribution channels over to your house and finally out of your faucet, a force is applied to it.

This force, i.e., the water pressure, coupled with the size of pipelines in your house, determines the water flow.

If you are using city water, your local water board ensures that you receive adequate water pressure at all times. However, it may fluctuate due to many factors, including the time of the day or season.

So, does your house have adequate feed water pressure? Here’s how you can find out.

  • Ring your local water utility and ask them for the water pressure they provide.
  • If you aren’t satisfied, just use a pressure gauge to get a reading. However, it’s ideal to test multiple times and then average the result to get a correct estimate.

trickling faucet

Here’s how to a pressure gauge.

  • Ensure all taps and water-using appliances around the house are off.
  • Next, hook a gauge on a faucet nearest to the point where water enters your home.
  • Then, turn the faucet on at full capacity. Finally, check the reading on the gauge.

In case you own a private well, the scenario is a little different. A well system relies on a pressure pump, pressure tank, and pressure switch to build up pressure.

If you are experiencing continued slow water pressure, a common complaint, you need to adjust the pressure switch. It is located at the pipe connecting the well to the pressure tank.

Factors Affecting Water Flow and Pressure Around Your Home

Water flow rate is measured in gallons per minute (gpm), while water pressure is measured in psi (pounds per square inch).

On average, water pressure can fluctuate between 30 psi to 80 psi. Nevertheless, the ideal water pressure to ensure proper flow (for an average household) is 60 psi. Here are a few influencers that regulate water pressure and flow.

Where You Are Located

Water pressure is greatly affected by how far or close you are located to the water source. It’s important to remember that water pressure built up at the utility will reduce depending on the terrain and size of the distribution network.

Not to forget, some cities have tall water towers that store water at a height. Typically the primary function of a water tower is to collect water and help pressurize it for distribution. As water gushes down the tower, each foot of height adds 0.43 psi of pressure. If you are located near one, chances are your household’s water pressure is rather excellent!

Water Usage

When multiple people and appliances use water simultaneously, chances are, the water pressure will drop.

It may be frustrating to stand in the shower with the shampoo stinging your eyes, but it can easily be fixed by timing your chores and planning water usage efficiently.

Time of the Day

Unsurprisingly, you may notice low water pressure at peak hours of the day – for instance, early morning on a weekday. At odd hours though, the pressure will stabilize at its optimum level.


Whether big or small, a leak in any faucet or pipe around the house will cause a noticeable loss of water pressure. If you experience a sudden pressure drop, it’s wise to look for dripping taps or leakages in the pipelines.

It’s important to remember that acidic water with a high pH level speedily corrodes pipes. Besides leaching dangerous contaminants into your water, corroded pipes can break down and begin to leak.

Build Up Due to Hard Water

If you have a hard water supply, as many Americans do, your pipelines may be suffering from hard water buildup.[1]

The hard cake-like scale limits the flow of water, bringing it down to a trickle.

Moreover, hard water can calcify showerheads and aerators, considerably reducing water pressure.

Wrong Size of Pipes

The size of the pipeline that runs through the house should be in accordance with the size of the house and the number of members living in it.

Unless the pipelines are big enough to accommodate enough water, the pressure will keep going down.

Does a Whole House Water Filter Reduce Water Pressure?

Do Whole House Water Filters Reduce Water Pressure thumbnail

Yes, and no! Whole house water filters don’t affect water pressure as long as they are:

  • Sized adequately according to the family’s requirements, and
  • Maintained responsibly.

That said, cartridge-style filters have a higher chance of influencing water pressure than backwash filters.

Too Small of a System

Regardless of the type of whole house water filter you end up buying, you will experience a pressure drop if it’s not sized correctly.

Why is that so? You see, all units have a particular volume and speed at which they can treat water. For example, if a whole house water filter is designed for a four-person household, it will fail to provide enough water for an 8-person family.

Either consult a water professional to help you size your unit or bring out a calculator and do the math. List down how many faucets or appliances typically run at the same time and figure out an estimate. Here is a table to help you:

  • Bathroom taps: 1-2 gpm
  • Kitchen taps: 1.5-3 gpm
  • Showerheads: 2.5 gpm
  • Toilet flush: 3-5 gallons
  • Dishwasher: Approx 10 gallons per load
  • Washing machine: Approx 25 gallons per load[2]

Clogged Filters

As mentioned before, whole house water filtration systems will not function perfectly if the filters are clogged. As water filters begin to clog with contaminants, it takes more time for water to pass through it to the other end. Ultimately, water pressure is compromised.

Doesn’t sound like a problem? After all, you always change your whole house water filter cartridges on time! Sorry to break the news; it’s relatively complicated. The optimum time to replace a filter cartridge varies from home to home – depending on how contaminated your water is and your daily requirements.

You need to be vigilant about filter performance and keep track of how often you need to replace them.

Unsuitable Water Filter

If you install an ultrafiltration system to treat “almost muddy” water, your unit will clog in no time. Not only will you continue to consume unsuitable water, but the pressure drop will also be annoying, to say the least.

How Can You Improve Water Pressure?

Here are a few tested tips to improve water pressure and flow around the house.


If the plumbing in your house is severely affected by hard water, you can install a water softener to save it from further buildup.

Another option is to use electronic descalers or water conditioners based on TAC (Template Assisted Crystallization) or NAC (Nucleation Assisted Crystallization). They claim to dissolve old scale from pipelines plus prevent any further deposits. There are, however, a few limitations for these systems to be effective.


Before rattling the ends of Earth and spending hundreds of dollars on technicians, it’s best to check the main feed valve at your place. Sometimes, you accidentally leave it halfway closed and forget about it until the pressure drop becomes traumatizing.

Faucets and Fixtures

Sometimes the problem is isolated to a specific faucet or fixture. It’s probably blocked due to dirt or served its life. The solution? Take it apart and inspect it carefully. Replace broken parts, clean stuck-on dirt, or soak it in vinegar to remove limescale deposits.


In conclusion, water pressure and flow rate aren’t identical.

In a sense, water pressure measures the speed or force at which water flows.

Water flow determines the amount of water that flows at any given time.

In your home, both can be affected by where you are located within the public water distribution system, your water usage, the time of the day, leakages, buildup inside your plumbing system and pipe size.

The installation of a whole house water filter can lead to a drop in water pressure and consequently flow if it’s undersized, the filters are clogged or you chose the wrong filtration method.

If you want to improve the situation you can clean your pipes, make sure all valves are fully open and check faucets and fixtures to make sure it’s not a point-of-use issue.

Further Reading


Meet Jason Hollow

Jason Hollow Jason is the founder of Water Masterz and head of content creation. After six years in the industry, he has tremendous knowledge and first-hand experience on all things related to water treatment.

His credo: Not a single American should have to drink unhealthy water at home.

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