As you know, swimming pools are used in villas, hotels and resorts. Also, recreational swimming pools and water parks have become popular in cities today. Due to the direct contact of pool water with humans, it causes the transfer of pollution from the person to the water and vice versa, which ultimately causes diseases related to the pool. For this reason, pool water purification and disinfection should be done periodically and permanently. In the following, the pool water purification process and its common methods are explained. How is the pool water purification process done? The process of purifying the pool water starts with filtration and the water passes through coarse filters such as garbage collectors and fine filters such as carbon sand filters respectively. After removing all contaminants, then the disinfection and clarification process begins. At this stage, by injecting chemical substances such as chlorine, bromine or ozone, it destroys all water microorganisms. In order to purify the pool water and keep it clear, different methods should be used. If the proper process is not implemented, the water may change color due to the growth of algae and your pool will become a suitable environment for the growth and proliferation of bacteria.