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How to Filter Well Water for Pool? Find Out All Easy Steps

Fact checked by Stephen Conklin

how to filter well water for pool

Are you thinking about filling your swimming pool with well water to reduce operating costs and give joy to your family come summer? Making such a decision is straightforward if you know how to filter well water for pool use.

You should first test your water. The reason is that well water has a different composition compared to pool water from a reputable supplier. It can contain various minerals that can affect pool water quality and microorganisms that can harm swimmers.

That is why filtering the well water with a suitable filter is essential if you want to use it in your swimming pool. Here is how in detail.

Table of Contents

Things You Need for This Tutorial


You will need at least two things for this tutorial.

1. Well Water Test Kit

Filtering well water requires knowledge of the substances you want out of the water. That is why a well water test kit is indispensable. You cannot assume that all well water is the same with precisely similar chemical composition.

You can purchase well water test strips from popular online shops or a local store that sells these products.

2. Water Filter

The water test kit gives you an idea about the substances present in the well water. You must decide whether to allow these compounds and particles into your swimming pool or not.

If your well water has mostly minerals that harden the water, you might want to invest in a water softener.

Some wells have dirt, small stones, and other sediments in the water. If these are your principal concerns, a sediment filter is an excellent choice. This water filter type is inexpensive and easy to maintain.

If you want a more robust system, a multi-stage whole-house filtration system is a wise choice. It incorporates a sediment filter, a CTO membrane, a carbon block filter, and other filtration membranes. The downside? These filters are often expensive.

Steps to Filtering Well Water for the Swimming Pool


Step 1. Test your well water.

Water testing gives you an idea of the substances, particles, and organisms present in well water. For example, the water test kit can provide information about water hardness, bacteria, fluoride, pH, copper, iron, and lead levels.

You can purchase a well water test kit from your favorite online commerce shop, although I recommend the VARIFY Complete Water Test Kit. It can check 17 water parameters to help you in making a decision.

Get a well water sample and dip the test strip. Compare the color change to the interpretation chart to give you an idea of your well water parameter’s existing level.

A more definitive test is to bring the water sample to a local laboratory.

Step 2. Choose the correct water filtration system.

Using the well water test results, you can choose the correct filter for filling pool with well water.

In general, a whole-house water filtration system is perfect for such a project. Ensure the filter has several filtration layers, including a sediment filter, a CTO filter, and a post-filter.

A reverse osmosis system is ideal in most instances, provided you also include a sediment pre-filter. This water treatment system can remove total dissolved solids, toxins, and harmful microorganisms from well water. Unfortunately, it can clog easily because of its tiny pore size.

If your well water has high mineral content, you might want to include a water softener after the water filtration system. A water softener replaces hardness minerals with potassium or sodium ions, making the swimming pool water more pleasant on the skin.

Step 3. Install the water filter.

Once you have decided on the water filter system to fill the swimming pool with well water, you can install it following the manufacturer’s instructions.

The filter should be between the well and the swimming pool. Installing the water filter is easier if you have existing plumbing from the well to your house. You only need to cut a section in the water supply line to fit the water filter.

Connect the compression fittings to the cut pipe ends and secure each to the water filter system’s inlet and outlet ports. The pipe coming from the well must join the water filter at its inlet port, while the tube going to the swimming pool will connect to the filter’s outlet section.

This Old House has an educational video about whole-house water filter installation. It may not be for the swimming pool, but you can get the tricks for installing one in your pool.

Step 4. Retest the well water.

Fill several cups with well water and perform the test again. If you think the test kit results are inaccurate, I suggest bringing the well water sample to a laboratory for testing.

I would advise you to keep a record of the initial water test readings. You can compare the before and after results to determine whether the water filter addressed your concerns.

Doing this step before filling the pool with well water saves you a lot of hassle. You can prepare other materials if the test results are less than spectacular.

Step 5. Fill your swimming pool with well water and adjust the parameters

You are now ready to fill your swimming pool with filtered well water. Many swimming pool technicians recommend filling the tank over a few days – two to three days is sufficient.

I also recommend testing the well water in your swimming pool after filling it. Testing a full-sized swimming pool is different from assessing a well water sample.

At the minimum, it would be best to check the chlorine and pH levels. These two parameters are essential if you want to treat a pool filled with well water.

You can add baking soda (to increase the pH) or muriatic acid (to decrease the pH) to the well water. If the chlorine level is high, you can add a chlorine neutralizer. Pour liquid chlorine if the chlorine level is lower than normal.


Knowing how to filter well water for pool is one of the essential steps to using well water for the swimming pool. It is a cost-effective solution that can also provide other benefits to the rest of the house.

If you think this tutorial is beneficial in filling your swimming pool with safe and clean well water, sharing this article with your acquaintances will help spread the knowledge. Questions, comments, and feedback are also welcome.

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