SWIMMING POOL

A swimming pool, swimming bath, wading pool, or simply a pool, is an artificially enclosed body of water intended for swimming or water-based recreation. There are many standard sizes; the largest and deepest is the Olympic size. A pool can be built either above or in the ground, and from materials such as metal, plastic, fiberglass or concrete.

Pools that may be used by many people or by the general public are called public, while pools used exclusively by a few people or in a home are called private. Many health clubs, fitness centers and private clubs have public pools used mostly for exercise. Many hotels and massage parlors have public pools for relaxation. Hot tubs and spas are pools with hot water, used for relaxation or therapy, and are common in homes, hotels, clubs and massage parlors. Swimming pools are also used for diving, other sports, and training of lifeguards and astronauts.

Pools must be sanitized to prevent growth and spread of bacteria, viruses, algae and insect larvae that can cause disease. This is done by using filters, ensuring pools have adequate flow rate and chemical disinfectants such as chlorine, bromine or mineral sanitizers. As the adverse effects of chemical disinfection on health and the environment become known, healthier, ECO friendly alternatives are sought.

Most pools in the world are measured in metres, but in the United States pools are almost always measured in feet and yards. In the United Kingdom most pools are in metres, but older pools measured in yards still exist. In the US pools tend to either be 25 yards (SCY-short course yards), 25 metres (SCM-short course metres) or 50 metres (long course). US high schools and the NCAA conduct short course (25 yards) competition. There also exist many pools 33⅓ m long, so that 3 lengths = 100 m. This is sometimes jokingly referred to as "inter-course". This pool dimension is commonly used to accommodate water polo.USA Swimming (USA-S) swims in both metric and non-metric pools. However, the international standard is metres, and world records are only recognized when swum in 50 m pools (or 25 m for short 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.