My two great nieces went to there aunts house to swim. They came home with a rash. My niece didn’t think much of it but when they went back the youngest one said as soon as she got in it felt like something was stinging or burning her. She got out and won’t go back in. I don’t blame her well the aunts husband brought a test kit home from work said it was for test there discharge water. I don’t know what all it test I’m assuming it does not do CYA. And that the clorien was just a little low I’m sure they keep it between 1-4 PPM as that is what the pool store recommended and they think I’m crazy for keeping mine between 4-8. My CYA is 50. He said CYA has nothing to do with how much clorien u should keep in the pool. Ok. My question is what could cause a rash and just I will know ( in case I ever have that problem) what can I do about it. Slam it. But my pool is so balanced and clean I wound have this problem