Have your tried water that’s been left overnight, or even for another day? How do you think about the taste? Treated water’s added chlorine that takes care of microorganisms, but at room temperature they begin to multiply rapidly and can really get the things crazy. But that’s not what makes old water taste stale. For that we can thank carbon dioxide. After about 12 hours tap water starts to go flat as carbon dioxide in the air starts to mix with the water in the glass, lowering its pH and giving it an off taste. But it’s most likely safe to drink. However, back to those microorganisms. Be careful if…