| Hard water is water that has a high mineral | | | | leave hair rougher and harder to detangle. In |
| content. This content usually consists of high | | | | industry, hard water contributes to scaling in |
| levels of metal ions, mainly calcium and | | | | boilers, cooling towers and other industrial |
| magnesium in the form of carbonates. It is | | | | equipment. Hardness is controlled by addition of |
| estimated that more than 85% of the water | | | | chemicals and by large-scale softening with zeolite |
| used by consumers in the US can be classified at | | | | resins and ion exchange resins.Washing hair in soft |
| some level of "hard" water. The term "hard | | | | water will have a different result because it |
| water" was originally coined to refer to water | | | | leaves fewer insoluble deposits on the hair. |
| that was difficult or hard to work with. The term | | | | Hard water tends to make the scales stand up, |
| "hard water" was originally coined to refer to | | | | which makes your hair feel rough and tangly. |
| water that was difficult or hard to work with. | | | | Types of hard water a common distinction is |
| Hard water requires much more soap, shampoo, | | | | made between 'temporary' and 'permanent' |
| or detergent than soft water; and the minerals in | | | | hardness. Temporary hardness is hardness that |
| hard water can decrease soap's lathering | | | | can be removed by boiling or by the addition of |
| capabilities. A common distinction is made | | | | lime (calcium hydroxide). Permanent hardness is |
| between 'temporary' and 'permanent' hardness. | | | | hardness (mineral content) that cannot be |
| There are also common types of hard water | | | | removed by boiling. It is usually caused by the |
| depending on the ion found in the water. Hard | | | | presence of calcium and magnesium sulfates. |
| water causes scaling, which is the precipitation of | | | | Chlorides in the water, which become more |
| minerals to form a deposit called limescale. Scale | | | | soluble as the temperature rises. Hard water may |
| can clog pipes and can decrease the life of toilet | | | | be treated to reduce the effects of scaling and to |
| flushing units. It can coat the inside of tea and | | | | make it more suitable for laundry and bathing. |
| coffee pots, and clog and ruin water heaters. | | | | Soft water lathers better than hard water but |
| Similarly, the insoluble salts that get left behind | | | | leaves a "slippery feeling" on the skin after use |
| from using regular shampoo in hard water tend to | | | | with soap. |