Circulation involves continuously pumping the pool water through a water treatment system, in which part of it is treated and part of it is refreshed. Settling on the right circulation speed, for example, depends on various situational factors, such as the volume of the pool, the degree of contamination and the distance the water has to travel to the water treatment plant.
The flow of water is essential, not only to ensure the continuity of the treatment process, but also because moving water is less likely to attract bacteria, fungi and algae than stagnant water, which means that flowing water is already cleaner per se. In addition, circulation results in a better distribution of disinfectants in the pool water and in quicker heating.