A childhood belief about swimming pools

When I was about eight my dad told me that when you pee in the pool, it would turn red and follow you around so everyone would know. I used to tell people to swam in my pool not to pee because we had 'the detector', as if it was some well known mechanism. I still don't know if it is true or not... so if I let a little bit of pee come out in the pool, I swim very far away, very quickly.