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Home » Water Filtration Systems » Whole House Water Filter Pressure Drop Explained

Whole House Water Filter Pressure Drop Explained

By: Craig Smith
Last Updated:
Whole House Water Filter Pressure Drop Explained

Although adding a whole house water filter to your home is always a good idea, there is more that goes into purchasing one than just the desire to have it.

Several factors must be considered when choosing which of the many different available whole house water filter systems you will buy.

One of those considerations is how this new water filter will impact your home’s water pressure. Some types of whole house filters will lessen your water flow more than others.

That’s why I thought it would be a great idea to discuss the effect that a whole home water filter will have on your household water pressure and some steps that you can take to minimize these systems’ impact on the water flow through them.   

By the time you are done reading this article, you will have a much better understanding of how whole house water filters impact your home’s water pressure and what to do about it.

Understanding Flow Rate and Water Pressure


Many people look at water pressure and flow rate as being the same. Although they are close cousins, they do represent two totally different aspects of how water moves through your home.

It’s important to know these because your new whole house filter (also called a whole home, media, or point of entry water filter) will affect them.

Water Pressure

Water pressure has more to do with the forces acting upon your home’s water flow as it moves from point A to point B. 

This includes gravity and water pressure has nothing to do with the speed that water flows through your plumbing and the devices that are on your home’s water line.

You can determine your home’s water pressure by purchasing or borrowing a simple water pressure tester that will attach to an outside spigot.


Once it is attached, simply shut off all of your taps and appliances that use water in your home and then open the spigot and take a water pressure reading.  

Flow Rate

Unlike water pressure, the water flow rate has everything to do with speed. It’s usually measured by determining how many gallons of water pass through a given point in your plumbing in a minute; appropriately called gallons per minute (GPM).

If you want to get a rough idea of the demands on the water flow of your home’s water supply, here are some useful approximations of what the different types of water exit points around your home require for a flow rate when being used:

  • Bathroom taps: around 1 GPM (gallons required per minute of use)
  • Kitchen faucets: 2 to 3 GPM
  • Showerheads: As much as 2.5 GPM
  • Washer: Around 3 to 5 GPM
  • Dishwasher: 2 to 4 GPM

As you can see, if several of these are being used at the same time, it can cause a significant impact on the water flow rate through your home.

Factors Influencing Water Pressure/Flow

When your home’s plumbing system was designed, whoever did that was aiming to create a system that maintained a steady water pressure of around 40 to 70 PSI.

Several things can influence your home’s water pressure/flow as it relates to point of entry filters. Some of the main one’s are as follows.

Improperly Sized Water Whole House Water Filter

Why is it important to not install a whole house water filter that does not impact your water flow and water pressure too much?

It’s because having a system that’s too small can impact the demand for water at the various exit points on your home’s plumbing system.

Your Water Source

  • City Water

How your water comes into your home will influence the way that water flows through your plumbing and its associated pressure.

The water pressure and flow from municipal water supplies are determined by such things as how high the towers are that help create pressure in the system and how well their piping distribution system is designed.

Obviously, you have no control over these.

  • Well Water

Well water pressure and flow are determined by the size and type of pump you use to draw water from your well. That’s why well water users have more control over the water pressure and flow through their homes.   

Plumbing Pipe Size

It only stands to reason that the larger the size of the plumbing pipes in your home, the fewer restrictions on water flow and pressure you will have in that system.

The number of bends in a plumbing system will also impact pressure and flow because each one lessens it.

Household Users

The more people that are doing things around your home that require water will also impact your home water supplies flow and pressure. This includes when showers are being taken, washers are being used, and your lawn is being watered.

Time of Day

You may have noticed if you are on a city water supply that the water pressure in your shower is better at night than during the day. That’s because the demand for water in your community is less at night than in the morning.

Do Whole House Water Filters Reduce Water Pressure?

The answer to this question is definitely yes. Anytime water meets something such as filter media it has to work harder to push on your water supply system. It’s just the nature of resistance as it applies to all things including household water flow.

How much pressure is lost? Unfortunately, I cannot give you a one-size-fits-all answer for this.

That’s because there are so many possible point of entry water filter setups that are manufactured or can be put together.

It’s the type of filter media in these systems that determines just how impacted the water flow through a whole house filter is.

For example, filter media such as reverse osmosis membranes and activated carbon block filters will reduce water pressure in your system much more significantly than granular activated carbon media or water softeners.

You also have to keep in mind that you need to balance your water pressure needs against the quality of the drinking water that you desire.

For instance, good whole house reverse osmosis systems may cut down on your water pressure but they will also greatly enhance your water quality.


So, you can’t be singularly focused on maintaining great water pressure through your home’s plumbing system when you set out to purchase and install a whole house water filter.

Lots has to be considered and come together to keep your water pressure at an acceptable level while increasing the purity and healthiness of the water that you drink and use.

Tips For Improving Your Water Pressure/Flow

Here are some ways that you can make sure your water flow and pressure through your whole house filter are always good.

  • Properly size your new whole house water; get professional help from a plumber or other water filtration expert if you are unsure how to go about doing this. The importance of getting this right cannot be underestimated.  
  • Keep your system clean. Any blockages or water pathway obstructions can hinder the water pressure/flow through your plumbing.

This includes adding a good water softener that helps prevent hard water minerals from building up inside of plumbing pipes.

  • Replace filter elements as necessary. This is because the media in the filter elements in your point of entry water filtration system will become clogged up over time and restrict water flow. The manufacturer of your whole home water filter should list filter element lifespans.
  • Make sure your valves on your water supply are fully opened or positioned correctly. Little things can make a big impact on the water flow and pressure through your home’s plumbing system.
  • Valves such as those found on your POE filters bypass plumbing that are not properly positioned can significantly reduce water flow.  
  • Consider hiring a plumber to check out your system. They can often spot problems in your home plumbing lines and associated components that are impacting your home’s water pressure/flow.
  • Add a booster pump to your home’s plumbing system. It’s a simple way to increase the water flow through your plumbing if you are currently dissatisfied with that.
  • Run a backwash cycle on whole house water filter components that have them during pressure drops. This applies if you have a salt-based water softening system or a single tank media filter that requires periodic backwashing. They can seriously reduce water flow and pressure in your home if not kept clean.

Water Pressure is Always a Consideration When Setting Up a POE Whole House Filter

There is simply no way around it, no matter what type of whole home filter that you install, there is going to be some pressure drop.

Keep in mind also that it’s often a good tradeoff when it comes to significantly improving the quality of the water in your home by adding a whole house filter and sacrificing some water pressure.

However, that should not mean that to get purer home water that your showerhead only trickles water out when using it.

If you research and plan your point of entry water filtration system properly, then you should never have to put up with significantly reduced water pressure to enhance your home’s water quality.

Also, make sure you follow the tips here to maintain your water supply system’s pressure and consult with a plumber or other water filtration system professional before you install a new system and if you are experiencing unusual drops in water pressure.

If you follow the advice here, having improved water quality while maintaining adequate water is by no means unreasonable to expect.  

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Craig Smith
Craig got his start in water working in the swimming pool and spa industry. Water treatment would grow into his main career but he ended up working in the pool industry for over 26 years where much of his time was spent balancing the water in customer's swimming pools and installing water filtration equipment. Craig offers an abundance of water treatment knowledge after helping homeowners get pure water for 26 years.

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