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Swimming pool

A swimming pool is an artificially enclosed body of water intended for recreational or competitive swimming.

One can distinguish private and public ones; the private ones are usually outdoors; for the public ones we can distinguish those outdoors, those indoors, and complexes with both. In some parts of the world, a swimming pool for private use is considered a status symbol. Swimming pools can be constructed either above ground (generally constructed from plastic and metal), or in the ground (usually concrete lined).

Swimming pools generally contain water to which much chlorine has been added to prevent the growth of bacteria and algae. One alternative form of chlorination is to have a salt water pool, where the chlorine is produced directly in the pool water by electrolysis. Some recent studies have suggested that swimming pool chlorination may contribute to higher rates of childhood asthma, leading to the development of (currently expensive) chlorine-free pool filter systems, which sterilise the water exposing it to powerful ultra-violet light.

The correct management of a backyard swimming pool is a difficult and time-consuming task. The chemical balance of the water has to be carefully monitored to make sure that it does not become fouled with algae, or grow too much bacteria. Either of these will make the water smell and look unpleasant, and can be a serious health hazard. The water must also be kept clear of debris such as fallen leaves and sticks, as these encourage fouling, and they become very slippery and dangerous as they start to decompose. Most people keep their pool either covered over or drained entirely during the months of the year in which it is not in use, as this is the easiest way to keep it sanitary. Public and competitive swimming pools are generally indoor pools - covered with a roof, and heated - to enable their use all year round. It is always advisable to keep a close watch on small children around swimming pools, as drowning is a major cause of child deaths.

Public pools are often found as part of a larger leisure centre or recreational complex. These centres often have more than one pool - for example an indoor heated pool, an outdoor saltwater or unheated chlorinated pool, a shallower 'children's pool', and a paddling pool for toddlers and infants. There may also be a sauna area. In the swimming pool area and/or in the sauna area there may be one or more jacuzzis, see below.

If a swimming pool (sometimes combined with facilities for allied sports and activites, such as a diving tank) is in a separate building, the building is called a "natatorium".

Many public swimming pools are rectangles either 25 m or 50 m long, but a backyard pool can be any size and shape desired. There are also very elaborate pools, with artificial waterfalls, varying depths of water, bridges, and island bars; they may belong to a hotel or holiday resort.

Swimming pools designed for competitions are required to be a certain length and depth to guarantee that a 200 m race will always be 200 m long. Many public swimming pools are 50 m long and 25 m wide which is a requirement for Olympic and World Championship swimming. Professional pools also require a minimum depth of 2 m, which is less common in general public pools and there are also regulations about other characteristics such as temperature, guttering and lighting as defined by FINA. Public pools are generally indoors - covered with a roof, and heated - to enable their use all year round. Competition pools have to be indoors to comply with the regulations regarding temperature, lighting and to protect the needed Automatic Officiating Equipment.

An 'Olympic Swimming Pool' is 50 m in length ("long-course"), 25 m wide, with 8 lanes of 2.5 m each. The water should be kept at between 25 and 28 °C and the lighting level at greater than 1500 lux. Recently "short-course" swimming events held in a 25 m pool have become popular (if not held at the Olympics). There also exist many pools 33 1/3 m in length, so that 3 lengths = 100 m. This is sometimes jokingly referred to as "inter-course". In general, the shorter the pool, the faster the time for the same distance, since the swimmer gains speed from pushing off the wall after each turn at the end of the pool.

In the US pools measured in yards are still common. In the UK most pools are in metres, but older pools measured in yards still exist. In the US yards pools tend to be fractions of 100 yards (25 or 50), whereas UK non-metric pools are more likely to be based on 110 yards. However, the international standard is metres, and world records are only recognised when swum in 50 m pools.

Jacuzzi

In the swimming pool area and/or in the sauna area there may be one or more jacuzzis: small pools where people sit on an underwater bench along the edge, with water streams and air bubbles. Dress code is in accordance with the area it is in: either swimsuit or nude. The water temperature is usually very warm to hot, 30 to 40 °C (86 to 104 °F), so that one can only stay a limited amount of time in it, but sometimes only mildly warm, in which case one can stay long if one likes (unless perhaps to make room for people who are waiting to get in when it is crowded).

Dress code

In public swimming pools dress code may be somewhat stricter than on public beaches, and in indoor pools stricter than outdoors. For example, in countries where women can be topless on the beach, this is often not allowed in a swimming pool, in particular indoors. See also Swimsuit.

Some public swimming pools have regular hours for nude swimming.

See also

External link

• Nude swimming hours in the Netherlands (in Dutch)
• Maintaining a pool with minimum chemical usage (in English)