Guide: How to Make Your Own DIY Whole House Water Filtration System

Author: Rory Mullan - Published: 2021/06/16 - Updated: 2022/11/08

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Even long before the invention of the whole house water filter system, our ancestors used various methods to purify water.

If you’re feeling experimental, you can DIY a water filter system, too, at a fraction of the price. Given that your creative mind cannot rest since you first heard about the possibility of DIY-ing a whole house water filtration system, you’re at the right place.

We’re going to discuss everything you need to know about the DIY process. So, get your tools ready and free up your weekend. Here’s our guide on how to make your own whole house water filter!


  1. Get your water tested by a laboratory to know what you’re dealing with and what filters/systems you would need to use.
  2. The key principle is to connect different kinds of whole house water filters one after the other.
  3. It is best to choose industry standard sizes for the largest selection of filter cartridges.
  4. Having basic plumbing skills is also a prerequisite and you must have experience in using the necessary tools.

Is Making Your Own Home Water Filtration System Worth it?

As much as we love DIY, it’s better to consider if the effort is worth it or not. So before we proceed to show you how to make your own water filter, let’s weigh the advantages and disadvantages.


  • Perhaps the most significant advantage of a DIY whole house water filter is the cost-saving. While the latest models can cost you anywhere around hundreds to thousands of dollars, a DIY version will be relatively inexpensive.
  • The process of building a filtration system from scratch means you know the system in and out. Therefore, if the system malfunctions, it will be easy to point out what went wrong. Similarly, maintenance and repairs will be right up your alley.
  • Depending on how contaminated your water supply is, you can completely customize every filter stage. Add or subtract any components that are required to configure the best arrangement.
  • Apart from the filter elements, this DIY project only requires a few basic supplies available at most local and online hardware stores. Bring out your toolbox and put the pipes and nuts to good use that you’ve been saving all along.
  • If you have the know-how of basic plumbing around the house, this project is a great way to polish your skills. We all love the satisfaction when we accomplish a technical job, don’t we? Time to show off to friends and family!


  • Not all of us have the time and technical knowledge to construct a homemade water filter. The fact that it requires several hours and a learning curve means this DIY isn’t for everyone.
  • There is no way to certify that the water purified by your homemade water filter is 100% safe. Large-scale manufacturers test their whole house water filters for safety and performance. So while you may have done an incredible job, there is still a window of uncertainty.
  • Homemade systems need regular maintenance and may have to be replaced more frequently if you unknowingly use low-quality materials.
  • Sizing a filtration system is pretty high-tech. However, unless you get the size correct, the effectiveness of the whole system goes down.
  • Many DIY water filters aren’t big enough to purify water for the whole house.


While homemade water filter systems seem like the best solution to save a few bucks, they’re not the best option for long-term scenarios. Consequently, many factors limit their usage, including potential threats to safety and performance. For one, they may not catch some or most of the dangerous contaminants present in your water supply.

Hence, for most users we advise against substituting conventional water filters with homemade versions unless it’s an emergency.

In essence, it’s always best to reach out for tried and tested water filter systems made by expert engineers and certified by NSF.[1]

How to Make Your Own DIY Whole House Water Filter

DIY Whole House Water Filtration System Thumbnail

Now that we’ve weighed the pros and cons of constructing a water filtration system, it’s time to learn how you can make your own DIY whole house water filter.

We shall discuss what you need to do before you roll up your sleeves. Next, we shall elaborate on how to make several types of whole house water filtration systems. Finally, we’ll also explore how to fix the system to your existing plumbing.

Plan Ahead

Like all DIYs, it’s crucial to plan so you can wrap your mind around the idea.

Most importantly, if it’s a large-scale project like this one that requires time, do your homework and research about the best way to do the job. It doesn’t work like your middle school science project; a tiny mistake can lead to wasted time, money, and effort.

As mentioned earlier, this DIY project requires mechanical and plumbing skills.

If you’re a novice, you can seek help from a friend who already attempted to build a DIY Water filter system.

Moreover, you must know how much water your family needs in a day to size the filter accordingly. Multiply the number of your family members by roughly 80 gallons or check your water bill for an exact amount.

Test the Water

You can’t build an efficient water filtration system unless you know which contaminants you’re dealing with.

For example, is your water hard, or is it polluted with sediments and dirt? To combat the issue, you first need to pinpoint the problem.

If you’re using city water, you can either request a report[2] from the water board that supplies water to your area or individually test it from a laboratory. In the case of well water, you need a laboratory test to highlight specifically which harmful elements are present.

Buy your filter components accordingly to enjoy water that’s clean and tastes and smells better.

Gather Essential Tools & Supplies

You might have plenty of the essential tools lying around if you’ve ever done any plumbing job around your home. You can also borrow any of these from a friend if you don’t plan on using them again.

  • A handy drill and some universal drill bits
  • Any tool to cut pipes of varying thickness, e.g., pipe cutter or hacksaw
  • Wrenches and screwdrivers
  • Tubing and connectors
  • Shut-off valves
  • Bypass valves
  • Pressure gauges

Understanding Filtration Systems

Now on to the most important thing: The water filter system itself! Assuming that you know what you’re filtering (iron, manganese, sediments, lead, chemicals and so on), purchasing the various components is simple.

Filter Housings & Cartridges

There are four standard sizes of filter housings and corresponding cartridges:

  • Size 1: 5” x 10”
  • Size 2: 5” x 20”
  • Size 3: 5” x 10”
  • Size 4: 5” x 20”

Why use standard sizes? Because it allows you to switch between manufacturers and brands without the need to worry about compatibility. You can also test various types of filter media etc. in order to target different water contaminant groups. And, by not being bound to proprietary filters from a single company, you can potentially save a lot of cash.

Anyway, select the filter size according to your household requirements. If you’re specifically looking for a whole house water filter, then size 3 or 4 is usually the best option. But this entirely depends on your number of family members and their water usage patterns.

The bigger the filter housing and cartridge, the faster the filtration. This also translates to lesser filter changes required due to delayed clogging.

Understanding Microns

Some water filters, like sediment filters, are rated in microns. Let’s understand the concept of this to help you put together a better whole house filtration system.

1 micron is equal to a millionth of a meter or a thousandth of a millimeter. Or, let’s say a single human hair is equivalent to around 70 microns. So when a system claims that it can filter substances that are as small as 1 micron, that symbolizes meticulous filtration.

However, meticulous filtration translates to a lower water flow rate since the water has to pass through a highly dense filter. So ultimately, water pressure in your sinks and faucets may be compromised. And the more filter stages you add, the more impact it brings on the water pressure.

Assembling the Filters

In an ideal world, your water will be spring fresh and free of chemicals. But unfortunately, in the real world, you’re probably dealing with multiple unwanted substances in your water.

So depending on your water quality, you should configure a couple of filter stages to achieve pure and clean water.

Thereby, you use a step-down approach to remove the bigger particles first and then the smaller ones. You can achieve this by installing one filter stage after the other. Here’s an example:

  1. A 20-micron sediment pre-filter traps dirt and other large particles. This prevents clogging of the following filter stages.
  2. A 5-micron sediment pre-filter traps the finer sediments.
  3. An activated carbon filter stage neutralizes bad tastes and odors, and reduces harmful contaminants such as lead and chemicals. You could even use two of these; granular activated carbon first, followed by a carbon filter block.
  4. For chloraminated tap water: Use catalytic activated carbon.
  5. For iron-laden well water: Use an iron filter cartridge.

different water filter stages

Regardless of the type or types of filters you plan to use, double-check they’ve been NSF-certified or at least tested. It’s the only way to make sure that they’re indeed effective. Also check which contaminants will be reduced and to what percentage.

Setting Up Additional Features

Once you’ve assembled the water filters, it’s time to add a few functional valves to make the system more efficient.

Off-the-shelf water filter systems flaunt plenty of features to make operations smoother. Although you can’t achieve the same level of engineering, adding a few valves and gauges will make your setup highly functional. Here are a few options that you can add-in.

Shut-off Valves

Set up a shut-off valve before and after each filter cartridge to quickly stop and start the supply to each stage. When a filter needs replacement or cleaning, you can simply use the valves to stop the water supply without hassle.

Bypass Valves

A bypass allows you to continue using water in your home even when your DIY whole house water filter is being serviced. You can learn how to bypass a whole house water filter here.

Pressure Gauges

The pressure gauge is another highly functional accessory that measures water pressure. Install one before and after each filter element, or before and after the entire setup. A heavy fluctuation in pressure indicates that it’s time to clean or replace the filters.

Installing the Water Filter

Once you’ve set up your home water filter, it’s time to install it to the plumbing in your house. If you’ve made it so far, chances are you’re already familiar with the following process. So let’s go through a few pointers to help you.

  • Remember plumbing codes.
  • Shut off the main water supply before meddling with the plumbing. Accordingly, drain the remaining water from the lines.
  • Select a point of entry where your water enters the house so you can have clean water in every tap. The location should be easy to access for future servicing.
  • Try to use the best quality materials, including washers, tapes, and fittings, to avoid constant repairs.
  • In order to create a good seal, wrap all threads with Teflon tape. Also, grease O-rings before positioning them correctly.
  • Check for leaks and fix them on the spot.
  • When done, remember to prime the different filter materials through flushing with water. This will also remove any installation debris.


In conclusion, making your own DIY water filtration system isn’t too complicated and can potentially save you a lot of money.

But you need to plan ahead and should have your water tested beforehand. Then you can choose the right filter elements accordingly.

When putting everything together, consider adding handy accessories like shut-off valves and pressure gauges.

For the final installation, follow our pointers listed above.

Further Reading


Meet Rory Mullan

Rory Mullan Rory has joined the Water Masterz team as a contributing writer. He has covered all sorts of topics in the last several years.

Outside of his writing work, Rory enjoys photographing the Irish landscape and making music!

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