I see a lot of comments in these threads regarding the old idea of a red cloud to indicate someone has peed in the pool. This idea never dies and I think I know

I see a lot of comments in these threads regarding the old idea of a red cloud to indicate someone has peed in the pool. This idea never dies and I think I know where it started... When I was a lifeguard, we had to test the pH levels of the pool water every few hours. This entailed taking a sample of water, adding a few drops from a dropper and noting the shade of red the sample turned. We would tell the kids that we were checking that the "pee detector" was working. I really think this is what has fueled the notion that it's possible to turn pool water red to catch pool pee-ers. PS - I cannot recommend a summer job lifeguarding to anyone teenager, it was honestly one of the best jobs I ever had.