Sustainable practices for landscape design: natural pools
A natural pool or natural pond is a system consisting of a constructed body of water, where the water is contained by an isolating membrane or membranes, in which no chemicals or devices that disinfect or sterilize water are used, and all clarifying and cleaning of the water is achieved purely with the motion of the water through biological filters and plants rooted hydroponically in the system.
Plants actually act as a water cleaner.
Basically, there are 3 different systems: where plants are integrated in the pool, where plants are out of the pool, and a hybrid system.
Particularly me, I would really like to touch the plants and its roots when inside the pool…what an exhilarating experience that would be! Combined with natural stone, this would look truly natural.
Natural pool are generally divided into 2 areas: the one for swimming and the one for the regeneration zone.The regeneration zone consists of a lined overflow pool filled with specific filtration substrate (gravel, sand or lavastone) and flora. Plants used for water regeneration can be supplemented with decorative flowering species to create an attractive water garden environment. The biological processes that clean the water take place in this zone.
The swimming zone should be physically separated from the regeneration and should reach a depth of 2 m (6 ft 6 in). The regeneration zone and swimming zone must be equal in area for sufficient purification. The swimming portion of the pool can look like a conventional swimming pool or a natural pond. The regeneration zone can be placed adjacent to the swimming area or in a remote location depending on the space available.
In a natural swimming pool water flows via gravity from the swimming pool into distribution shafts. The water then passes through a biological fine filter/bioreactor before it is pumped into the regeneration zone. Plants in the regeneration zone are planted in the substrate, and these plants compete for nutrients that would feed algae. The water is cleaned biologically by the metabolic processes found in the substrate in which the plants are rooted. Thus, microorganisms and the water plants ensure effective, continuous cleaning.
Because of their reliance on natural environmental factors, each pool system is built with consideration to the region and climate where it’s installed. Construction elements such as the biological filter and the combination of contaminant ridding plants vary with each pool.