Honestly, I heard it first from my sister-in-law who lives in California, USA. She said that more and more Americans preferred this kind of pool over the traditional chlorine pool. Not only that it has less expensive treatment cost ( pool supply are more environmentally friendly) but mainly because of its medicinal advantage. Unlike pure chlorine pools which create organochlorines that can mimic human hormones. Of course this will eliminate the side effects chlorine that can cause cancer, asthma and immune system disorders . I wish the technology is available here in our country. Have you heard of it?