Let’s check in with some earlier hypotheses about water hardness.
- hardness is a specific measure of minerality (TDS) for limited, “industrial” purposes
I still wholeheartedly agree. I might rephrase and say “hardness is a measure of a specific subset of minerality…” etc. But I realized something else about the use of “hardness” to describe water taste. Here’s a definition from the Water Quality Association:
“Hard water is water that contains an appreciable quantity of dissolved minerals (like calcium and magnesium).
Soft water is treated water in which the only ion is sodium.”
This is one of many muddled definitions I’ve seen where hardness is erroneously used to describe minerality. Let’s reiterate: hardness is a measure of multivalent cations, like calcium and magnesium. There are many minerals that can be dissolved in water that don’t make water hard, like sodium. There’s no such thing as “soft water”; there’s only water that’s been made less hard, or “softened,” by substituting something like sodium for magnesium or calcium. And the WQA is a trade association that represents companies that sell things like “water softeners.” Water softeners will cut down on scale in your pipes and appliances, but they won’t necessarily make your tea water taste better.
Continue reading ‘Hardness 2’