Water hardness refers to how much Calcium and Magnesium is in your water. Water rich in Calcium salts is considered "hard".
hard water. Compare with water softener. Hard water is water contaminated with compounds of calcium and magnesium. Dissolved iron, manganese, and strontium compounds can also contribute to the "total hardness" of the water, which is usually expressed as ppm CaCO3. Water with a hardness over 80 ppm CaCO3 is often treated with water softeners, since hard water produces scale in hot water pipes and boilers and lowers the effectiveness of detergents.
The U.S. Department of the Interior classifies hardness based on the grains per gallon (gpg) concentration of the hardness minerals. To put this in perspective, a typical aspirin equals about five grains of material. If the aspirin were dissolved in a gallon of water it would add 5 gpg of "aspirin" to the water. Where hardness is concerned, water containing 1-3.5 gpg of the hardness minerals calcium and/or magnesium is classified as slightly hard; water in the 3.5-7.0 gpg range is considered to be moderately hard; at 7.0-10.5 gpg water is considered to be hard; and very hard water is classified as water with concentrations greater than 10.5 gpg. (Conversely, Soft water has a hardness of less than 1 gpg.)
a measure of the ability of water to form insoluble precipitates when boiled or when soap is added. Hardness is caused by the presence of Ca, Mg and Fe cations and to a lesser extent, other divalent cations. It is expressed as ppm of divalent cations. It can be measured with a water hardness electrode, which exhibits almost equal response to all divalent cations.
The amount of dissolved minerals in ordinary water, ranging from 50 parts per million (ppm) to 800 ppm in most municipal water supplies.
Hardness is caused by calcium and magnesium salts. Hard water requires more soap and synthetic detergents for washing and contributes to scaling in boilers and industrial equipment. Inland water supplies are usually very hard and require considerably more chemical additives during treatment.
A measure of the amount of metallic salts found in water. Hard water can inhibit the action of some surfactants and reduce the effectiveness of the cleaning process.
The amount of metallic salts, such as calcium, magnesium or iron dissolved in water. These can form in soluble "curds" with some surfactants and reduce the effectiveness of the cleaning.
Soluble metal salts, (principally those of calcium and magnesium, and sometimes iron and manganese) that when present in water in sufficient amounts create cleaning problems. These metal salts remain on a vehicle after the water evaporates leaving white spots.
The combined dissolved calcium and magnesium content of water. Usually expressed as parts per million (ppm), calcium carbonate (CaCO3). 1 gram = 17.1 ppm CaCO3 1 Clark? = 14.3 ppm CaCO3 1 German? = 17.9 ppm CaCO3
