Here’s the really fun part. If you open a bottle and drink from it, you’re introducing your mouth germs into the water. Leave that bottle for a week, and those germs throw a party.
How Long Can You Keep Water In Plastic Bottles at Albert Hoopes blog
Studies show that opened, warm water can grow bacteria within days. It’s not lethal, but it’s definitely a joyful microbe rave in your drink. You’ve been warned.
Tap Water vs. Bottled Water: The Showdown
Tap water can last indefinitely in a sealed, glass container. Plastic bottles are the weak link. They’re like that friend who always spills the gossip—they break down and share secrets with the water.
Fun fact: Some bottled water is just municipal tap water anyway. You’re paying $2 for the same stuff that comes out of your kitchen sink. Madness.
