How much mineral content is in hard water?
On One Hand: Anything less than a grain per gallon is soft.Hardness in water describes the presence of minerals that the water has absorbed on its journey from the spring or aquifer to the consumer. The most prevalent minerals are calcium and magnesium, and the U.S. Department of Interior defines any water with less than one grain of mineral per gallon as “soft,” while everything above that is at least “slightly hard.”On the Other: More than seven grains a gallon qualifies as hard.The Department of the Interior distinguishes between levels of hardness, and the threshold for “hard” water, as contrasted to “slightly” or “moderately” hard water, is seven grains of mineral per gallon. Anything above 10.5 grains per gallon is called “very hard.”Bottom LineAlmost all water has some level of hardness in the technical sense, so what the average person considers “hard” would probably need to meet at least the “Hard” threshold of seven grains of mineral per gallon.
