kokonaiskovuus

Kokonaiskovuus, often translated as total hardness, is a measure of the mineral content in water, specifically the concentration of dissolved multivalent cations. While calcium and magnesium ions are the primary contributors to total hardness, other metal ions such as iron and manganese can also be present and contribute to the overall hardness value. Total hardness is typically expressed in milligrams per liter (mg/L) as calcium carbonate equivalent (CaCO3) or in degrees of hardness, such as degrees of German hardness (°dH) or degrees of French hardness (°fH).

The presence of dissolved minerals, particularly calcium and magnesium carbonates, is what causes water to be considered hard. These minerals can originate from the dissolution of rocks and soil as water flows through them. High total hardness can lead to several practical issues. In domestic settings, it can cause scale buildup in pipes, water heaters, and appliances, reducing their efficiency and lifespan. It can also affect the lathering of soaps and detergents, requiring more to achieve the same cleaning effect. In industrial processes, hard water can cause operational problems and damage equipment.

Conversely, water with low total hardness is considered soft. While soft water may be desirable for domestic use due to the absence of scale formation and better soap lathering, it is important to note that water with extremely low hardness can have a bland taste and may leach metals from plumbing systems. The acceptable levels of total hardness vary depending on the intended use of the water, with different standards and guidelines in place for drinking water, industrial processes, and agricultural applications.