Why is ozone added in some water bottles? What's the use of it?
Ozone is used to treat water for drinking. It kills most organisms i water which causes water born infections.
It is better than Chlorine. ozone does not leave any residue in water,
"Drinking water treatment using ozone to remove iron, manganese, taste, ... Ozone has a greater disinfection effectiveness against bacteria and viruses ... This is one reason that the post-filtration system may include an activate carbon filter" from Wikipedia.