Nancy3 hello I looked up an answer to your question on the internet and your answer is the following as written below:
"Is chlorine water bad for vitiligo?
Swimming- Vitiligo is a sensitive skin disease and most of the times it gets aggravated after swimming sessions. The reason behind could be chlorinated water in the swimming pool, from which the skin reacts and as a reaction the patch starts growing. So it's better to avoid swimming in vitiligo condition."
Additionally, I'm advising you to visit a licensed dermatologist to receive medical information to benefit your skin condition. 😁