Does Pure Water Really Exist?

The short answer is no, in an absolutely technical sense

But a better question might be “Is pure water what I really need or want?”

Water is known as the universal solvent, and because of this property, the available water on the planet always contains something besides H2O.

“Pure water” is a term commonly used by all of us in everyday parlance. But it is only meaningful in context, that is, relative to some standard that defines its suitability with respect to a particular end use.  The end use might be getting your clothes clean in the laundry or making better coffee. Or increasing the energy efficiency and life of your hot water heater.

“Pure water” suitable for clothes washing might be defined as having less than 1 grain per gallon of calcium and magnesium hardness.  In fact, the term “hard water” was originally coined meaning water that was “hard” to wash in.  “Pure water” for drinking (or making coffee) might be defined as at least meeting or exceeding the EPA’s drinking water standards.

But in all of the above cases, the water could never be called “pure” in the technical sense, when defined as water that contains abolutely nothing else but H2O. In fact, water that meets the 18.1 mega-ohm standard for ultrapure water in the semiconductor manufacturing industry is generally considered the purest we can get water in real life.

This water is so pure (but not absolutely pure) that it would be corrosive to most plumbing systems or containers we could put it in, and must be continuously recirculated through point of use treatment immediately prior to its use for rinsing computer chips, because it just won’t stay this pure sitting in a container–the water will try to dissolve the container, or absorb gasses from the atmosphere.  This degree of purity is sufficient to prevent it from conducting electricity, and hence its utility in rinsing microchips with electric circuits made literally at the molecular level.

Well, you might say “if my water at home was this pure, at least I wouldn’t have to worry about accidentally dropping the hair dryer into the bathtub and electrocuting myself!” On a more serious note though, this water would not be good for the health of most plumbing systems because it would corrode them, and is not considered suitable for drinking, even though it is very “pure.”

The truth is that absolutely pure water doesn’t exist, either in nature, and even when treated with the most advanced technology available to us. As water quality specialists, we know how easy it is for consumers to be confused and mislead by the term “pure water.” That’s why we don’t throw the term around loosely.  It’s also one of the main reasons we’re here for you as Certified Water Specialists.  To help you understand what your water quality needs really are, and how to meet them.