What is hard water?
Water is considered to be “hard” if it contains calcium and magnesium. While most natural water supplies contain a certain amount of these two elements, most supplies range from 3 grains per gallon (gpg) to 50 gpg (or 51.3 mg/l to 855 mg/l). These substances leave a “film” or scale on surfaces that come in contact with the water. If left untreated, hard water will form lime scaling in pipes, water heaters, boilers, air conditioning systems, etc., causing efficiency and sometimes even permanent damage. For example, in water heaters just a sixteenth of an inch of scale can reduce a water heater’s efficiency by up to 15%. In fact, scale acts as an insulating material and thus lowers heat conduction. Depending on the amount of water hardness, soap consumption can increase by as much as 90%. Hard water can also result in the formation of soap curd that adheres to cloth fibers, glassware, dishes and other products and leaves an itchy or sticky build-up behind.
Hard water contains dissolved calcium and magnesium ions. Commonly referred to as “hardness minerals,” dissolved calcium and magnesium can cause numerous problems when present in a water supply. Whether it’s from a well or a municipal water utility, water usually contains these troublesome elements. Water hardness is typically measured in “grains per gallon,” an indication of the quantity of dissolved calcium and magnesium the water contains. In amounts as small as one grain per gallon, water is classified as “hard” to a certain degree. Most homes use water that is considerably harder. While many families choose to soften their water by removing the calcium and magnesium with home water treatment equipment, many don’t even realize they have hard water.
Hard water is generally defined as having more than 1 GPG (grains per gallon) of dissolved minerals in it (usually calcium, magnesium carbonate, and/or manganese). There is some argument as to what is an “acceptable” level of hardness. Consider those who do not have enough water. For them just having water is wonderful. For those that have an abundance of water and the income/means to improve their water quality, then it is a relative term as to what constitutes “acceptable” levels of hardness. The judgment ranges from a conservative “Soft water = 0 to 5gpg; Moderately hard water = 5 to 10gpg; Hard = 10 to 20gpg; Very hard = 20+gpg as well as others feel that the following is their standard: Soft Water = 0 to 1.0gpg; Slightly hard = 1.1 to 3.5gpg; Moderately hard = 3.6 to 7.0gpg; Hard water = 7.1 to 10.5gpg; Extremely hard water = 10.6+gpg. Our own opinion is that an unacceptable level of “hard” water is a relative term and that only you can “know” if the level that you have is accepta
When water is referred to as ‘hard’ this simply means, that it contains more minerals than ordinary water. These are especially the minerals calcium and magnesium. The degree of hardness of the water increases, when more calcium and magnesium dissolves. Magnesium and calcium are positively charged ions. Because of their presence, other positively charged ions will dissolve less easily in hard water than in water that does not contain calcium and magnesium. This is the cause of the fact that soap doesn’t really dissolve in hard water.
According to the U.S. Geological Survey, more than 85 percent of the United States geography has hard water. Hard water forms when naturally occurring minerals enter water sources. Over time these minerals are absorbed by groundwater. The two most common types of minerals found in hard water are calcium and magnesium compounds. The Water Quality Association of the United States defines hard water as water containing dissolved hardness minerals above 1 GPG (grains per gallon). The most common hardness causing minerals are Calcium and Magnesium. Levels of hardness are classified as follows: Soft Water – less than 1 GPG, Slightly hard – 1 to 3.5 GPG Moderately hard – 3.5 to 7 GPG Hard – 7 to 10.5 GPG Very Hard – 10.
