I hate chlorinated water since I know that chlorine, being one of the halogens, is poisonous. This chemical is in common use to treat water in tanks, wells, e.t.c. I do prefer boiling since any water treatmemnt targets potential pathogenic microbes present in the water. Another advantage of boiling is that the chemical compostition of water is not altered, and unlike chemical treatment. And boiling also is cheap and you won't spend a penny lighting a fire. What do you prefer, adding chemical substances to water or boiling it?