Maybe it is their love of Freizeit and Nature but the Germans are leading a stampede for natural swimming ponds across Europe. Very similar to natural garden ponds, they are specifically designed for swimming in clean, pure water that is free from chemicals. Specially designed ponds first appeared in Germany and Austria during the 1980s but they are gaining popularity throughout Europe with the first UK swim ponds appearing about a decade ago. There are several advantages, not least the aesthetic effect it has on the garden and the lack of chemicals in the water. However, whereas many believe they also offer a low maintenance option to private and public bathing, they do not entirely take care of themselves. The first pools were actually built in Austria but quickly spread into neighbouring Germany and Switzerland where they propagated very quickly, especially in the domestic market. In 1998, the first public pool was introduced so legislation was very quickly put in place to monitor and govern the designs and maintenance. Apart from their look of course, the main difference between swimming ponds and swimming pools is fundamentally the use (or lack thereof) of chemicals.
While swimming pools use chemicals, such as chlorine, to kill bacteria, a swimming pond relies on the water being cleansed naturally – using the purifying properties of plants. An important decision when opting for a ‘natural’ swimming pond is, therefore, is which plants to select. This will naturally depend on the soil chemistry which in turn is affected by the mineral composition, organic matter and environmental factors. Local designers would be best positioned to advise on this. Natural pools must have a thriving pond ecosystem. The plants and the gravel they are grown in act as biological filters so that the water in the swimming area is clean and soft. Filters to extract surface debris, such as leaves, and a pump to keep the water circulating through the planting area are also required. The main point, however, is to do without chlorine or other chemistry-related water treatment products. Without the use of chemicals to keep the water clean, however, it is even more important to make sure water quality is correct, whether in private or public swimming ponds. Using plants to cleanse the water naturally increases the possibility of microorganisms and other biological, chemical and physical components entering the system. There are many water quality variables in natural swimming ponds and bathing water in general, the most important of which include:
- Escherichia coli
- Pseudomonas aeroginosa
- Legionella pneumophila
- Cyano bacteria
- Parasites such as cryptosporidia
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