Swimming one of the few activities where all the muscles of your body are engaged in movement. That is why I like and prefer it above any other physical activities
Of course the self-propulsion of a person through water is very engaging. Do you love swimming too?
No words can describe my attachment to this kind of sport. At least once a week, i do swimming in a local gym hall that I have a membership of
I am not surprised it is in a gym hall as swimming is one of the top public recreational activities
We have a public pool recreational area in our neighborhood, but I prefer gym's swimming pool as it is more luxurious and clean
Of course they maintain Proper sanitation at the gym. That is why the water is clear and you stand a little chance of catching a disease 
Indeed. Publicly owned and shared places tend to get neglected often and thus the sanitation is always a concern
Most of them use the same routine methods. SOme of them are  a water filter to remove pollutants, disinfection to kill infectious microorganisms, swimmer hygiene to minimize the introduction of contaminants into pool water, and regular testing of pool water, including chlorine and pH levels.
I am quite aware of the methods service employees use to keep the water clean, but personally, I always prefer privatized recreational areas
water circulation. Disinfection normally in the form of Hypochlorous acid (HClO) to kill infectious microorganisms. Alongside these two distinct measures within the pool owners jurisdiction, swimmer hygiene and cleanliness helps reduce organic waste build up. 
Guidelines.
The World Health Organization has published international guidelines for the safety of swimming pools and similar recreational-water environments, including standards for minimizing microbial and chemical hazards. The United States Centers for Disease Control and Prevention also provides information on pool sanitation and water related illnesses for health professionals and the public
Swimming
Swimming is the self-propulsion of a person through water, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs, the body, or both. Humans can hold their breath underwater and undertake rudimentary locomotive swimming within weeks of birth, as a survival response.
Swimming is consistently among the top public recreational activities, and in some countries, swimming lessons are a compulsory part of the educational curriculum. As a formalized sport, swimming features in a range of