Water bottles are the ‘perfect environment for bacteria to grow’ – as we’ve seen from the horror pics on social media. Follow these steps to stay clean Environmentally friendly and convenient, reusable water bottles are on the rise . But on social media, people seem confused about how to clean them, and post horrifying pictures of mold growing inside . Water sourced from a municipal water supply is likely very clean, explains Kelly Reynolds at the University of Arizona, who studies water quality and disease transmission. Continue reading...