The water is a tasteless, odorless, colorless substance whose molecules consist of two hydrogen atoms and an oxygen atom. It is an indispensable element for the development of life. Something hard, on the other hand, is not soft, has resistance, or is rough.
Hard water is known as water that hinders the development of foam when in contact with soap, due to the fact that it has a high quantity of bicarbonates and carbonates of magnesium and calcium. To calculate the hardness of the water, we usually add the concentrations of magnesium and calcium that are present in each liter of water.
According to Digopaul, the opposite of hard water is soft water: the liquid that has a very small amount of mineral salts. When there is no mineral in the water (that is, when it consists only of hydrogen and oxygen), we speak of distilled water.
In addition to magnesium and calcium, the hardness of water is determined according to the amount of zinc, manganese or iron, among other cations (a cation is an ion whose electric charge is positive, which is why it is deduced that it has suffered a loss electron; its oxidation state is positive). According to the World Health Organization (WHO), this value should be expressed in milligrams of substances equivalent to carbonate per liter of water; when it does not reach 60, then we are faced with soft water.
The hardness of the water can be permanent or temporary. In the case of permanent hard water, however much it is boiled, the magnesium and calcium chlorides and sulfates are conserved since, after reaching a certain temperature, their solubility begins to decrease.
The hard water temporary, however, can lose their toughness when it is added calcium hydroxide or when boiled. This is because their carbonates can dissolve and therefore be removed.
It is important to know that hard water causes various problems. When hard water is used in clothes irons, heaters or heaters, washing machines or washers, and boilers, it is common for carbonates to become embedded in tanks and ducts. In this way, the appliances can be covered and stop working properly.
Regarding the impact that hard water can have on our health, the debate has not yet closed, since to face its detractors there are those who assure that its consumption is key to satisfy the need that our body has for magnesium and calcium. Some researchers point out that both positions present inconsistencies and lack of accuracy, so it is important to approach the subject with an open mind and focus on the evidence before making a final decision.
The hardness of water directly affects its organoleptic properties, that is, in all those parameters that we can use to describe its physical characteristics according to the perception that our senses have of them, among which are its texture, smell, taste, temperature and color.
The WHO ensures that water whose hardness exceeds 200 mg / l carries the risk of scale formation in tanks and pipes, while if it is below 100 mg / l, long-term corrosion can occur.
Leaving machines and pipes aside, there are experts who assure that in humans it can lead to the appearance of kidney stones, although none of the studies carried out specifically on this topic since 1984 have produced scientific evidence to support the risks. that many attribute to hard water. The general tendency, anyway, is to avoid its consumption in children and people with urinary problems.