Natural filtered pool in Avalon Estate

18 August 2021

A brief history of natural filtered pools

Natural filtered pools, natural pools or bio pools were developed in Germany and Austria in the 80s. Since then, according to a report published by the HCMA, an architecture bureau based in Canada, there are more than 20.000 natural filtered pools developed globally, and in Europe. Additionally, there are many more under development in North America.

The cleaning process of a naturally filtered pool is different from the other traditional ones. This requires a mix of filtering systems whose aim is to keep a clean aquatic ecosystem. The water that runs out of the swim zone is permanently recirculated through a regeneration zone where it is filtrated through gravel substrate layers.

Plants used

There are three types of aquatic plants that can be used to filter the pool water:

  • Floating plants such as lotuses and waterlilies.
  • Emerging plants occupy the edge of the pool such as different herbs.
  • Submersible plants that have the sole aim to oxygenate the water.

Advantages of natural filtered pools

We will briefly explain the benefits that natural filtered pools have over the traditional ones in the following sections.

1. Health and wellbeing

People with skin conditions or side effects to chemicals can rest assured that they can use the pool without having to worry about any respiratory or health-related reactions. This category includes infants, small children, and people with sensitive skin. Parents should not be concerned when their children take baths, as the pool does not use any chemicals for filtration.

2. Operational costs

Natural filtered pools represent an innovative way to convert the traditional pools with high operating costs. The gravity-fed filtration process can reduce overall facility energy use. Coupled with the elimination of chemical use, it can reduce overall operating costs.

3. Environmental quality

Green spaces are becoming a necessity sought by an increasing number of people, and a natural filtered pool offers a visually pleasing natural setting. Moreover, they blend in perfectly with the surroundings, and eliminate the concerns related to chlorine water drainage into municipal sewers. This way, there are fewer chemical infused water that flows into the running water system.

4. Ecosystem enrichment

As stated above, a natural filtered pool helps with creating and maintaining a balanced ecosystem, as well as water quality.

Avalon Estate

Avalon Estate is a unique residential project in Romania that focuses on investments in security and green spaces. Sustainability is a key attribute in Avalon Estate and can be seen in the landscape concept which includes a park of approximate 7.500m2 as well as the facilities offered to future residents. Such a facility is the naturally filtered pool about which we will briefly talk in the following paragraphs.

General details

The pool in Avalon Estate will benefit from a natural filtration system, will be 165 m2 and will be separated into two sections. The water for both will be filtrated by natural means (Ecozones) which surrounds the swimming area (Swim Zones). Moreover, the pool zones will be separated by two EcoFlo filters that will be hidden under the floor of the platform that separates the children’s pool from the adult pool.

The water will be circulated continuously between the two zones using subterranean piping between them. The bottom of the children’s pool will be gently sloped from the water level to 1m deep, while the adult’s pool will have a constant depth of 2m.

The access into the children’s pool will be made through a sloped entry while the adult’s pool can be accessed by a ladder leading off the decking or curved steps leading off the platform.
A circular stone platform will be created which will bridge the Lily zone and Ecozone. It will be built out of concrete and will be covered with natural rock cladding. A circular basin will be cast into the middle of the platform and a channel will link the water pumped into the basin back into the pool as an additional feature.

Construction method

As opposed to a traditional pool, a natural filtered pool needs a different construction method.
Firstly, the outer edge of the pool will be made from waterproof concrete. The walls that separate the swim zone from the filtration zone, and the filtration zone from the lily zone will be made of double skin, plastered masonry walls.

Secondly, all the corners and joints between the pool floor and walls will be curved to assure the tightness and easy cleaning.


The platform and the top of the dividing walls will be made from clad with natural stone. The type of natural stone will preferably match the stone used in the steppingstones and large bounders. The floors of the swimming zones will be left as plain, sealed plaster as this will make it easier to maintain.

The outer edge of the pool will be hidden with river boulders, which will also extend into the gravel bed to create a natural transition between the gravel bed and surroundings.

Plants and filtration

There will be 5 types of biological filtration systems that will filter the water sufficiently to support large crowds that use the pool. Additionally, they will keep the water extremely clear all the time for safe use by the residents.

The plants will be chosen by their filtering and landscaping capabilities. The species will be adequate to the climate and will be selected for flowering in seasons wherever possible. There will be a combination of herbaceous plants, ground covers, and shrubs, containing a mix of seasonal and perennial plants if the climate allows. This will offer a diversity of heights, colors and textures which will be designed in collaboration with the landscape artist to make sure that the pool ecosystem ensures its inclusion in the surrounding landscape.

Ionic enrichment

Ionic filters will inject beneficial ions into the water as the ultimate control and removal mechanism for algae. This is important in the summer season or during heavy usage.

Natural filtered pools utilize plants to maintain a healthy aquatic ecosystem, integrate well with the surroundings, and have multiple health-related benefits for the ones that encounter side effects to chemicals usage in traditional pools.

Avalon Estate is the only residential project with a naturally filtered pool that spreads over 165 m2.

Join the exclusive Avalon Estate community and enjoy the naturally filtered pool.

Discover more about the project and follow us for more interesting resident facilities! 

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