What's a magnesium pool like?

I found out recently that my dads done the training to convert swimming pools into magnesium instead of chlorine. Apparently it's the new craze. He's only one of 9 people in Australia who are qualified to do it so obviously it's not really popular yet here. So anyone in the US have their pool magnesium? I really am interested in hearing what it's like. Must be soooo good on the muscles.