GRAYL GeoPress Water Purifier Bottle, CNET's best budget water bottle: $100 at Amazon Apparently, the eight-by-eight rule came out of a void, because there's no scientific evidence to back it up.

Water bottles by Italian company You Bottles, in collaboration with street artist Banksy, are displayed at the Ambiente homewares trade fair in Frankfurt, Germany in Feb. 2025. (Kim Cook via AP) ...