What defines the hardness of water?
The Water hardness expresses the content of the latter in dissolved minerals, and in particular in calcium and magnesium ions. These ions being responsible for the formation of limestone, the more a water will be concentrated in calcium and magnesium ions, the harder it will be… and the more it will be limestone.
But how does water load mineral salts? Well when it crosses the ground, water passes through limestone rocks and through different geological layers; it then naturally loads with minerals! And as the composition of the soils is not the same everywhere, the hardness of the water varies according to the regions, and will not be the same in the North (where it is hard) as in the Massif Central (where the water is naturally sweet).
To note : the hardness of water has nothing to do with whether it is drinkable or not. Hard water is simply rather hard water! To find out the hardness of the water in your home, you can inquire at the town hall.
How to measure the hardness of water?
Already, know that there is a simple little trick to assess the hardness of water: put tap water in a saucepan and heat it. If there is a whitish deposit after heating, it is scale or lime, and this means that your water is hard.
But more scientifically, the hardness of water is measured with its hydrotimetric titer (or TH), expressed in French degree. A French degree corresponds to 4 mg / l of calcium, 2.4 mg / l of magnesium and 10 mg / l of limestone.
The waters are classified as follows:
- From 0 to 8 French degrees (° f), the water is said to be very soft;
- From 8 to 15 ° f, the water is said to be soft;
- From 15 to 25 ° f, the water is said to be moderately hard;
- From 25 to 42 ° f, the water is considered to be hard;
- Above 42 ° f, the water is said to be very hard.
In summary, when the hydrotimetric title of a water is higher than 15 ° f, we can consider it hard, and say that it is a calcareous water.
Water hardness: can it have daily consequences?
Hard water is therefore more or less calcareous water, but completely drinkable, and that you can drink without fear for your body. Moreover, since it is richer in calcium and magnesium, hard water can even be beneficial to health and protect against certain cardiovascular diseases.
On the other hand, the hardness of the water can cause problems with regard to household electrical appliances, which will end up with large deposits of scale on the walls, which will prevent them from functioning optimally. Not to mention that in the long run, hard water can end up significantly scaling your pipes.
In addition, soaps and other detergent products are less effective in hard water: for a satisfactory result, it will therefore be necessary to put more!
Can we fight the hardness of water in the house?
To fight against the hardness of water and to preserve your household appliances and your limestone installations, there is a simple solution:water softener. The latter makes it possible to discharge the water from the calcium and magnesium ions which it contains (and which promote lime) by replacing them with sodium ions, and therefore to obtain fresh water.