Calcium Hardness Testing

Calcium hardness is a measure of the amount of calcium ions present in the water.

A description of water as “hard” means that it has a high mineral content. These minerals are largely made up of calcium and magnesium carbonates, bicarbonates, chlorides or sulfates. The minerals get into the water mostly through washing over or through limestone and chalk rocks.

Total hardness of water consists of magnesium hardness and calcium hardness.

  • Drinking water –There are health benefits associated with hard water, as both calcium and magnesium are important dietary requirements. Calcium also improves the taste of the water. If the hardness of the water is too high, scale will form on taps and appliances such as kettles.
  • Pool and spa– Water hardness is an integral part of the water balance calculation, along with pH, alkalinity, and sometimes TDS and temperature. Water balance is important for swimming pools in order to maintain healthy and pleasant bathing conditions, and to prevent corrosion of the pool surfaces. The only method by which the hardness of the water can be reduced is by diluting the pool water with mains water which usually has a lower hardness.
  • Aquaculture– Water hardness is an important parameter that must be controlled in order to create the best environment for fish to grow. Calcium is important in the formation of bones and teeth, and also in other biological processes. High levels of calcium in the surrounding water will also prevent the fish losing sodium and potassium from their bodies. These two ions are essential to normal heart, nerve, and muscle function.


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Photometer 7500

The Photometer 7500 is Palintest’s top range photometer covering all major water quality parameters, with more than 80 test methods.

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Pooltest 6 Photometer

The Pooltest 6 provides simple and effective pool testing for service engineers and pool managers, with all the tests required for a water balance calculation.

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Compact and versatile, the contour comparator offers simple visual testing with a wide range of test options.

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