A natural pool does not impact the environment, but becomes part of the environment, filtering the water through the soil, without clarifiers, sanitizers or algaecides. Natural pools are also friendlier to the animal kingdom, and can provide a peaceful watering hole for birds, waterfowl, animals and other creatures too small to be seen. Using no pool chemicals means that your pool won’t pollute your local watershed or destroy ecosystems. Local plants can be used around the edge to absorb contaminants, provide more habitat areas, and oxygenate the water.

Once the pool size and shape is determined then its time to construct a retention pool for your filtration. This is separate from the natural pool and is below the natural pool by at least 2 ft and separated by a cement or rock  barrier wall. The construction for natural filtration of the bed surrounded by rock or stone and protected by a thick vinyl liner and an under liner. The bed that is constructed for filtration should be several feet thick, and best practice is to have a regeneration area equal in size to the swimming area. The fill is stratified to be capillary, accommodating plant roots which will in turn promote successful plant growth. Water plants and marsh plants are placed in a constructed bed of washed gravel, lime, loamy sand – which are the main ingredients for natural filtration. The water is pulled through the filtration bed by a circulation pump. A second pump is commonly used to pull water through surface skimmers and a bio-filter, and discharge it back into the pool. In addition, an aerator or waterfalls may be used to oxygenate the water.

By using hydroponic plants and shellfish that consume bacteria and contaminants, a natural swimming pool can be kept sanitary, without the use of traditional pool sanitizers. pH and alkalinity should still be managed in a natural pool, but other pool chemicals are not used. Minerals, UV or Ozone systems could be used as helper sanitizers – but this disqualifies it as a truly “Natural Pool”. Testing for bacteria levels is recommended if the pool is used for swimming. European natural pools maintain strict standards, and are able to achieve sanitary water without the use of chlorine or other purification methods. A blend of the right plants, combined with effective circulation and filtration, can keep a pool sanitary.

Aquatic plants provide shade, naturally filter out contaminants, and they also consume the nutrients that would feed algae. The plant selection would depend on what part of the country you are located in. Generally, you want to have plants in several depth zones. Floating plants like water lily or duckweed, rooted plants like cattails and bulrushes, and underwater plants like foxtail and hornwort to create a balanced biology in the water. Consult a local garden center that has some specialty in native water plants or hydroponics.

One thing to understand is that the main water cleaning activity is due to the micro organisms and microbes, not the water plants. The plants use nutrients from the water as food for themselves which helps prevent algae growth and contributes oxygen to the system. Although full equilibrium may take several months or years to fully develop for natural pools, micro organisms and microbes break down the potentially harmful pollutants into basic elements. A ‘balanced’ natural pool will stay clean and clear with very little work.

We have a big selection of polymer wall pool kits in many different shapes and sizes that can be used for a DIY natural swimming pool installation. You can be as creative as you want building your own natural pool, utilizing rock formations, water cascades or waterfalls. Once you figure out what size will fit then the planning starts. Remember that you should have a regeneration area as large and deep as the pool itself. On top of the pool walls, you can use stones to separate the swimming area from the regeneration area. Basically the water is pulled over the pool wall, into a large area where it filters slowly, pulled through by the circulation pump. Our natural pool clients usually go with a black or brown pool liner.

Seeing that everyone is going eco-friendly these days, the natural pool concept is … a natural! More homeowners and even public pools are going this route.

1. The Lodge Treehouse

2. David Wenzel Treehouse

3. Longwood Gardens