Water hardness – how can it be determined and changed?

Knowing the hardness of water is very important as it affects the performance and longevity of electrical appliances, such as washing machines or dishwashers. Most households in Germany have hard water. This means that the content of calcium and magnesium is high. In the following guide, you will learn how to set the optimum level of hardness, how to determine it yourself and what to look for in hard water.

Ein Geschirrspüler bei dem es oft zu einer negativen Wirkung durch Wasserhärte kommen kann

What exactly does water hardness mean?

The water supply companies in Germany must indicate the degree of hardness of the drinking water. It describes the concentration of calcium and magnesium ions in tap water, whose properties are determined by this content.

The degree of hardness is divided into the following areas:

– soft: less than 1.5 millimoles of calcium carbonate per liter, 8.4 ° dH

– medium: per liter 1.5 – 2.5 millimoles of calcium carbonate, 8.4 ° to 14 ° dH

– hard: per liter over 2.5 millimoles of calcium carbonate, more than 14 ° dH

The water hardness 1 corresponds to soft, 2 medium, 3 hard and 4 very hard water. Basically, therefore, the higher the proportion of calcium and magnesium ions, the harder the water.

Effects of hard water

With a high degree of hardness, there are some disadvantages: Hard water leads to the calcification of household appliances such as the washing machine, coffee machine or kettle. For the calcification of the heating elements of a washing machine, for example, the higher proportion of calcium bicarbonate is primarily responsible. In heating systems, too much calcium deposits reduce the pipe cross-section. Due to the insulating effect of the heat exchange is impaired. Lime deposits also favor function restrictions on components and corrosion. Hard water forms faster on faucets. The calcifications, which are also visible on many devices, are very unattractive and lead to increased energy consumption. The reason is that the lime conducts the heat on the heating rods worse. In addition, the life of the devices may decrease.

Wasserhärte hat oft negative Auswirkungen auf die Waschmaschine

Soft water is better in many ways

Soft water is best in many areas. For example, washing and rinsing requires less detergent and rinse. Hard water can affect the washing power of the detergent or reduce the cleaning effect. With soft water, you can not only use less detergent, but you can save the fabric softener while washing, while you should add it to harder water. For the preparation of tea, coffee or other delicate drinks and food soft water is also better, because hard water affects the appearance and taste negatively. The reason: With increasing water hardness, the taste of the drinking water increases.

Hard water is safe for your health

A high water hardness is harmless to human health. The hard water contains essential minerals: calcium is a very important building material for bones, teeth and blood clotting. Magnesium in turn has a very positive effect on the nerves, arteries and muscles. In addition, the mineral should be able to prevent a heart attack. Therefore, the legislator does not prescribe a standard for water hardness.

Announcement of the water hardness is obligatory

Water utilities must inform consumers about the hardness range at least once a year. The same applies to any change in water hardness, which is not just temporary. Possibilities of announcements are:

– stickers or flyers

– imprint on the water bill

– publication in the regional press

– communication on the company website

Measure water hardness by titration

If you want to measure the hardness of your tap water yourself, the so-called titration is suitable for this purpose. Use this procedure to measure the amount of titration solution required to fully bind the calcium and magnesium ions. To do this, drip the titration solution, which you can purchase from a specialist dealer or the Internet, into a test tube containing your water. After each drop, shake and check the color of the mixture. This process is repeated until the color changes from red to green. The required number of drops corresponds to the degree of hardness of the water.

Conclusion

Neither too hard nor too soft water is ideal. The optimum water hardness is 8.3 to 8.4 ° dH. Hard water tends to lime. If you regularly add suitable substances, such as water softener or regenerating salt, you can prevent or at least contain these deposits. A good alternative is a diluted vinegar essence or citric acid. Afterwards you should rinse with clear water. A water filter reduces the content of lime, chlorine and other substances. He ensures that you have to descale less often. In addition, it is possible to buy a water softening system that can be installed with little effort on the domestic water connection. Water hardness has hardly any significance for health and drinking water quality.