In the lovely weather today I took our youngest, 4 years old, to the swings. And forgot that there was a public paddling pool. She really really wanted to go in, understandably. But the water was not chlorinated and I know it just sits there day after day with scores of kids playing and peeing, algae growing, mosquito larvae etc. I'm not a massively fussy mum with hyper-hygiene standards and rationally I tell myself that if the pool was a health hazard they wouldn't fill it year after year (40 years ago my own mother wouldn't let me play in the same pool). But I just can't believe the water is truly safe, otherwise why would any public pool chlorinate or the instructions on the above ground home pools include daily chlorine?