Go Back

Natural swimming pools first started trending in the early 80s, in Austria. Many Austrians are great appreciators of a bracing swim in a crisp mountain pool, so Alpine resorts sought to create something as close to a mountain lake as possible. The results were certainly attractive, and since then, the natural swimming pool has enjoyed somewhat of a Renaissance, especially with sustainability coming to the forefront of the collective consciousness. However, the questions remain – how do you keep the water clean? Do you need a pump? What is the correct pond filtration system?

However picturesque a pool may be, guests or residents need to be able to swim in clean, safe water. In their earliest iterations, natural pools were filtered via a large area of vegetation. Nowadays, we have more knowledge about how to further improve the water quality by natural means, including maintaining water values such as pH, KH, phosphate, etc.

Naturalized water solutions – that is, a water feature that uses natural filtration and treatment substances – have advanced in leaps and bounds. We can now control water quality continuously, no matter the size. This offers possibilities not only for natural swimming pools but any naturally cleansed ornamental pond or pool. Here, we cover the key options, including pond media, mechanics, and treatment solutions.

The benefits of naturalized pools and ponds

Natural pools and ponds feature many benefits and advantages.  With state-of-the-art technology, these installations are actually pretty low maintenance. Along with their impressive sustainability credentials and ornamental attributes, they undoubtedly add value to commercial swimming facilities. Let’s break down these benefits below:

  • Integrable solution: Natural pools and ponds generate a habitat that blends in perfectly with the surrounding environment. They are also easy to integrate into new or existing installations.
  • Sustainable and eco-friendly: There’s no need to use chemicals for water treatment, so the pools and ponds have a low environmental impact. This means, in many cases, a 100% reduction in the use of chlorine and dilute acid.
  • Low maintenance: The natural and effective water treatment systems provide peace of mind and reduce maintenance tasks.
  • Ornamental: Natural pools and ponds are the perfect way to add a decorative touch to both indoor and outdoor gardens and green spaces.
  • User experience: The pools and ponds provide the opportunity to experience a unique and increasingly exclusive feeling of swimming in a natural environment.

Now let’s turn to the various configurations, including mechanical and treatment options, vegetation configurations, pond filter media, and more. With this information, you’ll be able to assess which type of naturalized pool or pond is best for your design or facility.

Types of pond filter media and their characteristics

Pure Nature

The Pure Nature model features a wealth of flora and fauna, which along with a small waterfall or fountain, serve to keep the water clean. The result is a rich natural environment full of color. Periodic cloudy water is normal, as in nature, but with regular maintenance (pruning the planting zones, vacuuming the bottom, etc.) the water will remain largely clear.

Since the walls of this type of pond are not free from algae and/or biofilm, the use of bacterial formulas is strongly recommended to improve water quality in general. This is especially the case in warmer climates, where algae grow more easily. Therefore, it’s important to note that this option is for those who want their natural swimming experience to be fully authentic.


The Natural model is more or less the same as Pure Nature but with the addition of a low-power mechanical filter. Maintenance and power consumption are still reasonably light using only skimmers, pond filter system, and UVC. There are three possible systems, described in the diagrams below.

The use of these tools makes the water algae-free and relatively clear. UV is an essential tool to kill the floating green algae that’s particularly unappealing to swimmers. Technically, a well-built natural plant/substrate filter can control algae by removing its sustenance, but this damages plant life that’s crucial for maintaining water clarity.


This type of swimming pond offers a natural experience, good plant growth, and diverse fauna. The pond filter media and mechanics, described in the diagram, guarantee clear water all year round. Maintenance is done periodically but backwashing filters must be cleaned regularly.

The most significant difference in the Clear model is the bead filter. The bead filter acts as a fine-mechanical filter, like a sand/cartridge filter, but with added benefits. After a few months of bacteria growth around the pond filter system, it can filter down to 5-10 microns without affecting backwashing capabilities. This is a very important distinction between this media and sand filters, which can block over time and are challenging to clear by backwashing. In a swimming pond, sand filters will work for a few months but then slowly start to block due to the biofilm that the naturally-occurring bacteria produce. This will clog the sand into big clumps that are difficult to remove by backwashing.

Crystal Clear

The Crystal Clear model guarantees clear water all year round, with limited flora and fauna. Low-energy pumps run 24/7 during the swimming season while a phosphate filtration system deprives algae of sustenance. Phosfree (lanthanum chloride) is also dosed automatically with a Dosatech dosing pump, whose built-in timer ensures the same dose is delivered every day.


Visually, the BioPool is a traditional swimming pool without plants, wildlife, or natural sides. The main difference is that the filtration and treatment system is chemical-free; instead, we use low salt hydrolysis systems to produce oxidants and a very, very low amount of chlorine, if necessary. By setting the redox value a lot lower than a standard pool (around 400mV instead of 700-750mV), the water has less chlorine than the average glass of European tap water.

Pond filter system: A version for every environment

Naturalized ponds and lakes are an ideal solution for a wide variety of spaces. Hotels and resorts that incorporate natural pools will add substantial value to their offering through their eco-friendly credentials. Meanwhile, these bodies of water can also enhance communal spaces, providing a natural, pleasant environment for guests.

Parks and gardens are also the ideal public spaces for integrating a natural pond solution, providing a touch of beauty, freshness, and tranquility to the public. Natural pools and ponds in residential communities and shopping centers also enhance the setting and add value.

As natural pools and ponds were initially designed in high latitudes and cold areas, it is necessary to design and evaluate the proper use of these type of pools depending on the location to be placed. Regarding regulations for naturalized pools and ponds, it is essential to carry out a specific design for each project and comply with the prescribed technical specifications in any case. No matter the location, natural pools can beautify the environment – fully sustainably and with less maintenance than you might think.

Freepool2 – An innovative technical solution
Fluidra presents a water treatment solution that…
Skypool – The most advanced technology
These pools are made of prefabricated galvanized…