a man pouring water from filter tap

The DIY Whole House Water Filter System (How-To)

The quality of water in your home is extremely important to your overall health. Everybody needs to take a proactive approach to knowing and influencing what goes into their bodies, and water is always involved in one way or another.

It is no longer enough to let the city or the state run the system for you. You have more control over things you can do yourself. Because clean, healthy water is a priority, today, we will show you how to make a whole house water filter system by yourself.

Water Filter Review

Get the Water Tested By a Professional

As much are you are handy with your workmanship, we advise you to outsource this to an expert. You will never be confident you diagnosed the water sample accurately enough and identified all the pollutants in it. The point of the whole house water filter is to cover both the aesthetics and safety angles of water treatment.

Different contaminants require different solutions, and knowing exactly what is present in your water will enable you to come up with a system that covers all angles. Your source of water has a bearing on the type of harmful contaminants you will be dealing with.

Well water has a higher concentration of sediment and hardness ions, for instance, while city tap water will be full of water treatment byproducts like chlorine and chloramines. The total dissolved solids vary from one location to another, and the variation will be more pronounced in well water.

The Filter System

The motivation behind any DIY house water filter system is to tailor the filtered water system to handle the specific contaminants present in your water supply. You will connect different filters with their unique specifications in series using a water path so that your water gets treated by all of them before it gets to your outlets.

Based on the test results, get a collection of filters that will constitute the symbiotic stages of the filtration process. Several considerations should influence your choice of filters for your water system:

The Size and Concentration of Sediment

A specialized sediment filter is mandatory for a well. It should be able to capture the organic matter and suspended solids in the water without significantly affecting the pressure and flow of water.

If the sediment concentration is high in your water supply, a small micron filter will get clogged very fast, the flow rate will be affected, and the filter will get damaged in the process. This applies to wells more than city water which comes partially treated. Larger micron sizes are recommended for well water.

The average range for house water sediment filters is between 500 to 25 microns, the higher figure for wells with a high concentration of organic matter and the lower one for city water. A larger micron size means many smaller particles will get through this stage; you will have to compensate for this with the subsequent filters.

The Most Prevalent Contaminants in the Water

Pathogens like bacteria and viruses need ultrafiltration with submicron ratings of less than 0.5. If these are concentrated in your water supply, it means you will have to sacrifice a bit of water pressure because these filters are not fast.

Alternatively, you can incorporate UV water treatment as it is a proven germicide. It will not remove the bacteria from the water but rather kills it, so it is no longer harmful. This allows you to retain the larger micron size and maintain water pressure without compromising health.

Dissolved organic compounds like pesticides and herbicides are common in well water if you live close to farmlands as they somehow find their way into the water. A reverse osmosis filter with specialized semipermeable membranes should form part of your ensemble if this is your situation.

City water undergoes a chlorination process to disinfect it and deactivate pathogens. Unfortunately, the chlorine used in this process has byproducts that remain in the water, giving it a rancid odor and taste. Your DIY whole house water filter should have a provision for handling this menace.

An activated carbon filter is best placed for this task as they trap chlorine and let the water flow past them.

Drinking Water Fountain

Setting Up the Water Filter System

Arrangement of the Filters

For maximum efficiency, the filter taking the heaviest load should be the first contact with the water. By default, it will have the highest micron rating, and it will take on the heaviest sediment onslaught.

Pleated filters work well as first responders because of their design. The pleats increase the total surface area for filtration, meaning they can capture quite a large amount of debris. They also spread the pressure evenly such that the water is not choked when passing through. This allows you to maintain steady water pressure.

If you are incorporating UV treatment, it should come at the very end because UV travels in a straight line and will be obstructed by any particles between the source and the water. Expect the least particles at this stage.

Number of Filters

Since we have established different filters with their unique specialization, you might be tempted to filter for every class of contaminant in our water. This is not physically possible because the more filters you have, the more pressure you lose between them.

To avoid losing the water flow completely within the water filter system, you should restrict the number of filters to a maximum of 3. Study their features and select the ones whose combined attributes will cover all your requirements.

Size of Filters

Large filters have a naturally higher filtering capacity because they have more real estate to work with. They catch more contaminants before they are due for replacement, and more water can flow through them at any particular point.

Consequently, they are better at maintaining the flow rate from source to outlet and will produce a generally higher rate than smaller filters.

That being said, not every household needs 4.5 X 20” filters. Filters sized at 2.5 X 20” are sufficient for a standard whole house water filter system with up to 3 bathrooms. You can choose the large filers with smaller microns for a smaller to get the finest filtration with a reasonable flow rate.


Avoid proprietary and OEM filters for your DIY jobs. They are usually customized according to the specifications of their mother products and will often not be compatible with your makeshift components.

Generic filters are interchangeable, fit in any housing, and attach to all your available plumbing components with similar dimensions. They are also easier to replace when the time comes.

best water filter for home


Step-Down Filtration

This applies to well water with a high sediment content. You can take out the sediment in stages, starting with a specialized sediment filter that is serviceable and reusable. This can be a high micron filter between 200 and 50-micron, subject to how bad the situation is.

You can combine these with a 20-micron and a 5-micron or a 5-micron and a 1-micron depending on the sediment on your first filter. It is advantageous to have the first filter pleated so that it can capture more contaminants without clogging.

Bear in mind pathogens are removed by sub microns with below 0.5 ratings. If pathogens were found in your water sample and the sediments don’t allow you to efficiently lower your micron rating, you may be forced to incorporate UV treatment at this final stage because they will pass right through your filter.

Activated Carbon Filter

An activated carbon filter is critical for regaining the aesthetic qualities of your water system, especially the crisp taste and elimination of odors in your clean drinking water.  A high percentage of this comes from the water treatment process, which means eliminating chlorine and chloramines.

They also help with some dissolved organic compounds like pesticides and herbicides if you are a well water consumer.

You can incorporate activated carbon filters in the final two stages to ensure none of that rancid chlorine taste and odor makes it out water filter system.

Some water supplies use chloramine to disinfect the water, which is too slippery to be stopped by your average activated carbon filter within the time that the water will pass through it. You should consider reserving one station for the more effective catalytic carbon filter.

This is activated carbon with a unique structure and a modified carbon surface, which can promote chemical reactions. It is capable of eliminating chloramines and hydrogen sulfide.

Reverse Osmosis Filters

Reverse osmosis removes lead, fluoride, bacteria on some level, and pharmaceuticals. It, however, works best if the larger sediments have already been removed to prevent fouling of the membrane. It also needs the water pressure to be reasonably high to work effectively.

It can be incorporated in the last stage of filtration.

Miscellaneous Functional Components

These are extra features you can include in your DIY whole house water filter system to make it easier to manage. They are not mandatory, but we find them handy.

Bypass Valves

You may prefer not to break the supply of water into the house when doing your routine service of the water filter system. This can be achieved by introducing a bypass option for the water to flow past the filter without getting into it.

The implication is that the house will be utilizing unfiltered water during this period. We advise that you service your system when there is the least demand for water so that you don’t expose your plumbing to untreated water.

Pressure Gauges

They help you to monitor pressure levels from the source and out of the filter system. The difference shows if the system is working efficiently, and it can also alert you if one or more of the filters are clogged.

Backwashing Drain

Because we recommended the first sediment filter to be reusable due to the amount of sediment, we need to enable the system to utilize this feature. A reusable filter is washable and can be used for much longer than the regular filter. It takes away the need for frequent replacements that will be costly in the long run.

Backwashing is necessary to dislodge the contaminants from where they were trapped on the filter before the sludge can be drained off, giving the filter a new lease of life. This works well with the pleated filters we recommended.

The drain can be built into the filter housing and the sludge directed to a suitable disposal area. This water can be used to water plants so that the energy used to pump it does not go to waste.

You can automate it by incorporating a timer that routinely opens the valve to facilitate the backwashing.

upper tank of the water softener system

Water Softener

Because we are building a whole house water filter system, we need to address this topic. A whole house system goes beyond just clean drinking water. It involves showers, dishwashers, laundry machines, and other appliances.

The other non-drinking applications run better with soft water. It makes soap lather better, it is gentle on the skin, nails, and hair when you shower in it, and it protects the entire plumbing system from scaling stains associated with hard water.

If we maintain this filter unit system the way it has been constructed, you will flourish if the hardness in the water is manageable. The setup is not ideal for the removal of hardness ions.

If the water is more than moderately hard, you will be forced to choose between installing a water softener in the whole house system or at the point of use for specific appliances and faucets.

Benefits of Building Your Own Whole House Water Filtration System

Here are some of the benefits of building a whole house water filtration system:

  • Doing it yourself gives you value for money because you exclusively buy filters that will deal with your existing problems and include accessories you will actually use.
  • It allows you to customize the setup to your personal preference in terms of water quality and accessories.
  • It is a permanent work in progress, and you can make any adjustments you need to when you need to.


And now here are some of the challenges you might face when building your own whole house water filtration system:

  • It is a long process that requires patience and resilience
  • The need to contract an expert to test the water from the source and eventually after it goes through your system. This is a costly affair

Taking a sip of tasty crisp, clean, clear water that has been poured from a faucet powered by your DIY whole house water filter on a hot sunny day makes the struggle seem like a tiny drop of water in the ocean. No one who successfully builds their own ever has anything negative to say about it.

Amanda Perkins

Amanda began her career as a technical writer for a healthcare group in 2008. Years after getting married and starting a family, she joined her husband Joshua on the Water Filter Authority journey to educate other families and households about safe, affordable, and effective water filtration systems.