pH stands for potential of hydrogen, and it’s a scale from 0 to 14 that measures how acidic or alkaline something is. Think of it as the mood ring of liquids: 7 is neutral, below 7 is acidic (like lemon juice), and above 7 is alkaline (like baking soda). Purified water, in its purest form, sits right at 7.0—a perfect, zen-like neutrality.
But here’s where it gets sneaky. Once water is exposed to air—say, from the moment you open that bottle—it starts absorbing carbon dioxide. That tiny chemical reaction can nudge the pH down to around 6.5 or 6.8, making it slightly acidic. Don’t panic; your tap water does the same thing, and your body is a master at balancing itself.
