Water hardness is a property that indicates the content of dissolved minerals (most commonly CaO and MgO) in water. Water hardness is important for its use as both drinking and utility water. It is a source of limescale formation and also affects the taste of water. It can be permanent or temporary. Permanent hardness contains dissolved chlorides, sulfides, nitrates, and silicates. Temporary hardness contains dissolved Ca(HCO3)2 (calcium bicarbonate). After it precipitates, CaCO3 (calcium carbonate) is formed, which is limescale.
Tester for measuring water hardness. The test consists of dipping the test paper strip into the water and, after one minute, evaluating the resulting color by comparing it with the included scale. The package contains 10 tests.
Protect the test strips from sunlight and moisture. Store in a cool, dry place at a temperature not exceeding 30°C. Do not touch the colored areas.