If you swim in pools you swim in pee. That's just life.
"A study at the University of Alberta, in fact, concluded that an Olympic-sized swimming pool was likely to contain about 225 liters of urine.
Which sounds like, to quote another of Sandler’s films, a shitload of piss. But, in a swimming pool, is it? The urine content of even the most urine-heavy of pools is, percentage-wise, minute. Those 225 liters of aforementioned urine are surrounded by enough water that the actual piss mass is less than one thousandth of one percent of the pool volume, meaning any pee-seeking dye would have its work cut out for it."