Water Hardness Scale
The water hardness scale is a measurement by which the mineral content of water is measured for its use. The vast array of processes, from drinking to industrial, that water is required for is staggering and of course the water has to be just right in order for the process to work correctly. All water begins as soft water with a low mineral content falling as rain. As it is an excellent solvent Water that has a high mineral content is usually referred to as Hard water, this is generally not harmful to health but it can cause havoc with industrial procedures.
The hardness of water is measured in a scale of grains per gallon, milligrams per liter (mg/L), or parts per million (ppm) depending on how the water is being used and measured. When looking at the water hardness scale EPA values are generally the industry standard for things like drinking water while there is no actual universal standard for hard water. The values set by the EPA on the soft water scale are divided into two seconds, Primary standards and Secondary standards. There is no standard for hard water but as far as soft drinking water goes the Primary are health considerations such as the lack of bacteria and the secondary standards are aesthetics like color and smell. Water that comes in from the mains generally contains certain minerals that are beneficial for health and therefore not filtered out, for example the calcium usually counts as between 5-10 percent of the recommended Daily Allowance for adults when consuming the full 8 glasses. As yet there has not been any research to suggest that hard water adversely affects human health.
Water hardness calculation is usually performed using data taken over a several year period with an average of 5 years. This is to insure that the results are an accurate average that will balance out any freak weather occurrences like heavy rain or drought. Water can either be temporarily hard or permanently hard depending on the type of ions present. Temporary hardness is caused by dissolved carbonate materials that give off negative calcium and magnesium ions. Permanent hardness is caused by the presence of negatively charged metal ions and in general cannot be removed either through boiling or softening. There is no standard international scale water hardness measurements and many simply go by the conversion offered by the EPA for their calculations.
Water hardness can affect many things in home, from how well your shampoo lathers to whether or not you will see a scummy deposit around the element in the dishwasher forming after several uses. Generally hard water is not noticed until it becomes a problem like clogging up a faucet or scaling up the heating unit on a washing machine. This is often why household appliances come with a suggestion to use “deionized water” since this will not cause scaling. In fact the most simple way to perform a water hardness test is simply to fill the sink with water and take a regular bar of soap and scrub your hands. If the water forms a white precipitate instead of a lather that clings in little solid bits to the edge of the sink then you have hard water. Though this is not the most scientific method and obviously for any industrial process they will use far more complex measurements including an alkalinity scale and other things to establish the purity of the water.
Often when you purchase new household electronics they will give a suggested water hardness for optimum use. Many families even purchase a water softening system to regulate the water flowing in to the house to give them optimum use and avoid these problems. A water softening unit will work with a water hardness scale conversion as to how much of the hardness the household wants to filter out. Generally these systems use sodium ions in the form of salt to replace the unwanted ions in the water system. When purchasing these units it is important to look at their water hardness scale GPG rating for how much they can convert per cycle for maximum cost effectiveness. Many household detergents even contain chemicals to soften the water as they work so buying a softener can be unnecessary. Most studies suggest that it is cost effective to only soften the water that goes into heating element units like water heaters and washing machines so as to prevent scaling but require less salt to fix the problem.
Water hardness is a perfectly natural occurrence, it certainly is far from dangerous when in a home setting though it can be quite inconvenient. There are two types of considerations when looking at water but these are generally only applied to soft or drinking water. Many families choose to soften their water so that they do not suffer the ill effects but they may be losing out on some of the potential mineral benefits found in the untreated water. Water hardness is usually measured by EPA standards but there are many ways to perform simple home tests and find out if your water is hard or soft without consulting a water hardness scale.