Kind of a deceptive video, which might make you think that if no one peed in the pool, there would be no pool smell. Urea is what reacts to create trichloramine, which gives off the smell. But urea, as the video acknowledges, also comes from sweat. Yet they go on to talk about chlorine reacting with urine as being the sole cause of the smell.

They should have gone into what percent of the urea comes from sweat vs. urine.