I have been swimming several times a week for the past 17 years. Before that I was a runner, running every weekday for 25 years with roughly 6 friends at 6am. My total distance was from London to Singapore and back.
A quick aside about exercise and health. Of the six of us, I had a heart attack at age 75 requiring a stent. One male runner and one female (a wonderful lover of mine) died before age 65 from cancer. One beautiful woman is still beautiful and healthy, another is very healthy, she is now a swimmer. The last one I’ve lost track of. For the sake of my blog readers I will contact her and see how she is.
My swimming pool just recently converted from chlorine to UV light. I love it. The water is much cleaner and the visibility is great. No burning eyes. San Francisco is slow on public health which is why this old technology is finally getting used.
How bad is San Francisco public health technology? I have been on both ends of chlorine.
From 1961 to 1965 I swam in a freshwater pool at the corner of Market and Van Ness (Oak St). It was a freshwater pool fed by an underground river from the Hayes Valley Aquifer. I loved the fresh unchlorinated water.
The city demanded the pool be chlorinated so the pool was closed. Now pools are allowed to have UV light in the recirculation system to kill all the biologicals that humans don’t like. An interval of 45 years.
Miscellaneous. I was on a kibbutz in Israel in 1959 where I helped build a swimming pool in a lovely small river. The water flowed through the pool without chlorine and no one ever seemed to have a problem. The pool in San Francisco at Market and Van Ness never had a reported problem either over half a century.