The Water hardness refers to the concentration of calcium and magnesium carbonates naturally present in water. The higher the calcium and magnesium content, the harder the water. Conversely, water with low dissolved salt content is soft water.

Water hardness results from its contact with rock formations during its underground journey. It therefore varies from one region to another depending on the nature and composition of the soils it passes through. For example, the Paris Basin is very calcareous, while Brittany and the Vosges Mountains are less so. Buy mineral water bottle

1°f is equivalent to 4 mg per liter of calcium and 2.73 mg per liter of magnesium. To find out the water hardness level of your tap water or the water supplying your appliances, you can either contact your water company or consult the report prepared by the Regional Health Agency (ARS) included with your water bill. You can also measure it using a test liquid sold in aquarium stores or test strips sold in pharmacies and other stores.

Water hardness assessment

Water hardness and limescale

Water hardness is also an indicator of the level of limescale in the water. Hard water will have a higher concentration of limescale because it is rich in calcium carbonates. Calcium carbonates naturally tend to precipitate, meaning they return to their solid form. In small quantities, limescale allows for the formation of a carbonate layer that protects pipes against corrosion.

But when hard water is heated above 61°C, an insoluble precipitate called limescale forms . It typically deposits in pipes, on dishes, and on the heating elements of household appliances such as kettles, dishwashers, and water heaters. These limescale deposits can affect the proper functioning and lifespan of these appliances and the condition of the pipes if left untreated. Limescale buildup on heating elements significantly increases energy consumption. Just one millimeter of limescale leads to an energy overconsumption of approximately 10%! Furthermore, hard water reduces the detergent properties of laundry detergents, soaps, and other cleaning products, requiring the use of larger quantities, which contributes significantly to water pollution.

If your water is very hard, you can install a water softener approved by the Ministry of Health. However, these devices must be checked regularly to avoid the risks associated with overly soft water, which can be harmful. Indeed, due to the absence of limescale, water that is too soft (less than 15°f) corrodes the pipe walls, leading to leaks. It also contributes to the degradation of water quality in the pipes and the growth of bacteria.

Hard water and its effects on health

Contrary to popular belief, drinking hard water is not contraindicated. Since there are no standards or maximum limits, the presence of limescale in water poses no health risks, and no toxicity has been identified in humans.

On the contrary, hard water is a natural source of minerals that the body needs , particularly for pregnant women and the elderly. As a reminder, the human body requires 1300 mg of calcium and 380 mg of magnesium. These are essential for bone health, muscle function, nerve impulse transmission, and blood clotting.

The calcium absorbed by the body is eliminated naturally, except in cases of severe kidney dysfunction. Contrary to popular belief, hard water and health go hand in hand. In fact, the presence of calcium and magnesium ions in water may even reduce the risk of kidney stone formation and offer protection against cardiovascular disease.