A childhood belief about swimming pools

I used to believe around age 5 That if you peed in the swimming pool water there's a special chemical in there that makes pee show up as the color purple. Boy was I scared to wee in the pool! One time when no one was looking I peed in the pool, and, to my surprise, all I saw was a few sprays of faint yellow spurt out into the water.

My Nana and PapPap told me this when I was really young to prevent little "accidents" in the pool. It worked for a while until I discovered the truth later on.