Water hardness

Water hardness: Measuring unity for the amount of calcium and magnesium salts in the water

Water hardness is a system of concepts of the applied chemistry which has developed from the needs of the use of natural water with his dissolved ingredients. Specifically the recompense concentration of the ions dissolved in the water of the alkaline earth metals, in special connections becomes with water hardness, however, also called their anionic partner. Calcium and magnesium ions as well as in tracks strontium and barium ions count in the essentials to the "creator of hardness". The dissolved "creator of hardness" can form indissoluble connections, before all lime and lime soaps. This trend towards the formation of indissoluble connections is the reason for the attention of the dissolved earth alkalis which has led to the origin of the concepts and theory around the water hardness.

• Soft water is more favorable for all uses with which the water is heated up, nevertheless, for washing, for pouring of indoor plants with water etc. However disadvantageous are the strong foam formation with detergents and the bad removability of soap, e.g., by the hand washing. Soft water is available in crystalline regions with granite, gneiss and basalt rocks. Also rainwater is soft.
• Hard water leads to the calcification of household appliances, raises the consumption of washing-up liquids and detergents, interferes with or promotes, according to the measure of the hardness, the taste and the appearance of sensitive dishes and drinks (e.g., tea). Hard water comes from regions in which dominate sandy rocks and lime rocks.

°dH (German hardness)

Relatively to the water is valid:

The water hardness can deviate from the given values according to season and amounts of precipitation as well as shares in spring water, ground water or sea water.