My dad once told me that this was done when he was young (so I'd guess around late 60's / early 70's). He told me it wasn't received well by the public, as swimmers (especially young children and older people) can loose some urine by accident. The dye in the water would damage their confidence.
Keep them in a separate pool or mandate pool diapers. Consider this thought experiment. You have a movie theatre where the people on the balcony may pee and that pee drips down on the faces of people below them. Would this be considered acceptable and would I be considered insensitive for complaining and insisting that those people wear diapers or else should not be in a place where their pee ends up in the faces of others? Why is it acceptable in a swimming pool?
> Keep them in a separate pool or mandate pool diapers
Pool diapers have roughly zero effect on urine (the whole reason for pool diapers is to retain feces in an environment where liquid absorbent diapers inherently will fail completely.) So, the pool diapers plan for dealing with urination is unworkable.
