DIY Natural Swimming Pool

A series of ponds in a nature landscape with a small waterfall.
  • 20-50 hours
  • Advanced
  • 1,000-80,000
What You'll Need
Digging tools (as simple or mechanical as you want)
Bentonite clay
What You'll Need
Digging tools (as simple or mechanical as you want)
Bentonite clay

As much as I love being out in nature, I am not such a fan of swimming in open bodies of natural water. There is a lot of research citing high bacteria levels and health concerns within unregulated ponds and lakes, and frankly I’ve seen Jaws one too many times to be comfortable cohabitating with unknown creatures of the deep. Yet this DIY is one I could get into! This article will feature instructions on how one can create a natural swimming pool in their own backyard. The pool, usually dug by hand, is kept clean without the need for chemicals or many commercial filtration systems and is self-maintaining, omitting the constant work a traditional swimming pool requires. Sound like something you might be interested in? Here's how to do it!

Step 1 - Start Digging

After first determining where you would like your pool, begin digging the hole. However, instead of digging a common "boxed" pool shape (with vertical walls and a flat bottom), it is pertinent to the success of this project that sloped walls are formed. In other words, a bowl-like effect should be created that boosts a one-foot vertical drop for every three horizontal feet.

It's also important to note that while there is no set regulation for pool size, it should be large enough so that at least 50% of the surface area is available for plants and roots to grow (something that will be further discussed in a later step). Also make sure that there are both deep and shallow depths that are able to host a variety of plant life.

Step 2 - Add Bentonite Clay

A bag of bentonite clay.

Before filling the hole, do a bit of research regarding the contents of your area’s soil to ensure when that when filled the water will not simply seep into the ground never to be seen again. The general rule for ponds and pools is that the higher the clay content, the better—an ideal concentration of clay would be around 20 percent. Should you find your soil to be less than stellar, your bowl can be sealed using an applied layer of bentonite clay. It's far cheaper than store-bought pool liners, and is a natural element that simply compacts the ground, making it able to hold water.

Step 3 - Filtration

As mentioned previously, this pool will require no chemicals or commercial pool filtration systems—it will only be regulated by the power of natural plant life. Recall how I mentioned that 50% of surface area should be left for natural herbage? According to experts, as water runs through the roots of plants placed in and around the pool, the fibrous root structures use their own healthy bacteria to form makeshift biological filters, removing pollutants and excess nutrients from the water. Furthermore, they possess “decomposing” organisms that eat bad bacteria in the water, helping to prevent the buildup of underwater waste without the need for chlorine or chemical boosters.

There are, however, some pieces of equipment that are always advised for the health of the water. It is a known fact that stagnant water breeds an excess of bacteria and pests, so it's imperative to keep the water moving. As this pool is man-made, an installation of waterfalls or an underwater aerator can be used to prevent issues before they begin.

So, what plants should one choose? Let's examine the best species of natural life to add to your DIY, making it both beautiful and a healthy place to swim. Most of these plants, if not in local specialty shops, can be found online inexpensively. I must, however, urge you to research each one individually to ensure they are in line with local and state importing regulations!

An underwater view of a pond with plants.

Carex and Scirpus: Tall, grass-like aquatic plants that sometimes bloom with small flowers

Typha angustifolia: Tall, green plants that have a brown tail toward the top of their stem

Pontederia cordata: Also known as pickerelweed, it's a beautiful lavender colored flowering plant

Sagittaria: Small greenery that grows best in shallow, partially submerged water or on muddy banks

Ludwigia: A kind of aquatic floral plant species that typically blooms with yellow flowers

Elodea: Also known as a waterweed, it's a green stemmed plant that can grow in both shallow and deep waters

Ceratophyllum: Also known as coontails, it contains small, bright green branched leaves. Tends to grow largely, and can fill a pond

Final Thoughts

After first filling the pool (with rainwater or a simple hose), levels may need to be touched up from time to time if weather has been exceedingly dry. A DIY natural pool is the perfect way to experience a warm afternoon outside, while enjoying and enhancing the natural wonder of your yard, so get messy and give it a try!