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