HARD WATER: THE WHAT, WHY AND HOW OF WATER HARDNES
Hard water, or water hardness, is a term you might be familiar with. Usually, it’s associated with problems with plumbing, appliances, cleaning and even skincare. We’re here to break down what hard water is, when it’s a problem and what you can do about it.
WHAT IS HARD WATER?
Hard water is water that contains a significant amount of dissolved minerals, mostly calcium and magnesium. The presence of these minerals prevents soap and detergent from lathering, instead creating an insoluble curdy substance in the water. This is the original reason it was called hard water – not because minerals and scale deposits are “hard”, but because the water made it “hard” to wash anything.
Water hardness is usually expressed in grains per gallon (gpg) or parts per million (ppm) as calcium carbonate equivalent. The Water Quality Association (WQA) and the American Society of Agricultural Engineers (S-339) define their water hardness scale as follows: