Swimming pool

From Academic Kids

50 meter indoor swimming pool
50 meter indoor swimming pool

A swimming pool, swimming bath, or wading pool is an artificially enclosed body of water intended for recreational or competitive swimming, or for other bathing activities that do not involve swimming, e.g. soaking, wading, water exercise, floating around on inner tubes, or merely cooling off on hot days.

One can distinguish between private and public ones: in warm parts of the world private ones are usually outdoors, while public ones can be outdoors or indoors, with some complexes having both. In some parts of the world, a swimming pool for private use is considered a status symbol (an indoor private pool even more so). Swimming pools can be constructed either above ground (generally constructed from plastic and metal), or in the ground (usually lined with concrete).


Water cleanliness and disinfection

Swimming pool water must be maintained with very low levels of bacteria to prevent the spread of diseases and pathogens between users. Strong oxidising agents are often used, especially simple chlorine compunds such as sodium hypochlorite. Other disinfectants include bromine compounds (very rare) and ozone generated on site by passing an electrical discharge through oxygen or air. When chlorine products are used these can be in the form of hypochlorite solutions and by dissolving Chlorine gas in water. Mantaining a safe concentration of disinfectant is critically important in assuring the safety and health of swimming pool users. When all of these chemicals are used, it is very important to keep the pH of the pool within a certain range (7-8), because either acid or alkali can cause chlorine gas to be produced. This is especially important in installations using chlorine gas itself because the reaction with water produces hypochlorous acid and hydrochloric acid which would make the water dangerously acidic if not neutralised.

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 ultraviolet light.

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Below ground, outdoor, irregular shaped salt water pool. Automated cleaner visible at far end.

Most people would not want to swim in a pool that appears dirty even if germs were under control. Therefore pools must be filtered to remove dirt. Also, to prevent buildup of chemicals, some water must be let off and renewed.

The proper 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 has not become fouled with algae or 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 become very slippery and dangerous as they start to decompose. Most people keep their pools 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 (draining however can be a serious safety hazard with deeper pools and re-filling can be fairly expensive in areas where water is scarce). 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, especially private pools that do not have professional lifeguards, as drowning is a major cause of childhood death. Adults are more likely to be aware of risks, but it is still a good idea to have more than one person around when using a private pool.

In public pools there is a much higher level of safety, with trained lifegaurds on duty whenever the pool is open. Because of the risk of drowning and the desire for greater safety, combined with technological advances that make such safety possible, more and more public pools are equipped with computer-aided drowning detection or other forms of electronic and sometimes automated safety and security systems. Among these are the Poseidon system, swimguard, and the Drowning Early Warning System (DEWS). Where safety and privacy are concerned, the trend seems to be toward safety.

Public pools

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Casual fun in a swimming pool.

Public pools are often found as part of a larger leisure centre or recreational complex. These centres often have more than one pool, e.g. 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.

If a swimming pool (sometimes combined with facilities for allied sports and activities, such as a diving tank) is located 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, fountains, splash pads, wave machines, varying depths of water, bridges, and island bars; they may belong to a hotel or holiday resort.

There are often lockers for clothing and other belongings. The lockers generally require a coin to be inserted as deposit. This discourages people from leaving the lockers locked and taking the keys.

Competition pools

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 require a minimum depth of 1 m and there are also regulations about other characteristics such as temperature, guttering and lighting as defined by FINA. Public pools are generally indoors and heated to enable their use all year round. Competition pools have to be indoors to comply with the regulations regarding temperature, lighting, and 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 33⅓ 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 are generally measured in feet. In the UK most pools are in metres, but older pools measured in yards still exist. In the US 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.


In the swimming pool area and/or in the sauna area there may be one or more jacuzzis (small pools in which 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: swimsuit near the pool, nude near the sauna. 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 as long as 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 outdoor pools. For example, in countries where women can be topless on the beach, this is often not allowed in a swimming pool, especially one indoors. See also swimsuit. A reversal of this strictness is also common, e.g. undress code in pools is stricter than beaches. Wearing shoes, and a shirt, on a beach is acceptable, but often not in a pool. Indoor pools have stricter undress codes than outdoor pools: in outdoor pools, men are often allowed to wear t-shirts for modesty or for protection from sunburn, but in indoor pools, men are not ordinarily allowed to wear t-shirts. Swimming with clothes on (for example, as practice for the prevention of drowning, as one might fall off a boat clothed) often results in objections from lifeguards at pools, especially at indoor pools. At beaches, many people swim with their clothes on and wear beachwear, whereas at pools (especially indoor pools) more minimal forms of bathing attire, such as lycra briefs for men or lycra one-piece tanksuits for women, are often worn. For diving from towers perhaps 10m high, sometimes bathing suits are doubled up (i.e., men will often wear one brief inside another) so that the swimsuit does not rip on impact with the water. While splashing around on beaches, especially on urban beaches, looser fitting bathing attire that is more modest is often worn.

Some public swimming pools have regular hours for nude swimming, and some pools even require nudity. Until recently, many YMCA pools required users to be naked or to have a bathingsuit made of materials that will not contaminate the pool; the words often used were "nylon bathingsuit or no bathingsuit". More recently, dress codes in many pools have been relaxed to allow for additional modesty. Many pool operators allow people to swim fully clothed if they can prove that they have a second set of clothes that are only for use in the pool, and if they are willing to go through the showers in this second set of clothes prior to entering the pool.

Other uses

Missing image
An astronaut prepares to descend into a swimming pool

Swimming pools are also used for events such as synchronized swimming and water polo as well as for teaching diving and life-saving techniques. They have also been used for specialist tasks such as teaching water-ditching survival techniques for helicopter crews and training astronauts.

See also

External links

de:Schwimmbecken es:Piscina fr:Piscine gl:Piscina it:Piscina (TO) nl:Zwembad ja:プール pt:Piscina sv:Piscina


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