You don’t need to be an expert to know that hard water can affect your hair. Notice how your locks feel different when you travel? It's because the quality of H2O varies from place to place, and harder water often contributes to hair damage, making it rougher and more brittle. It's fairly straightforward, water hardness depends on the amount of dissolved minerals—mainly calcium and magnesium.
Water starts as "soft," but when it flows through soil rich in these minerals, it becomes “hard.” So, if your water supply comes from the ground—be it a well, river, or lake—it likely contains some amount of calcium and magnesium. The more of these minerals, the harder your water.
I never realised how much the calcium in water could affect my hair until I moved from an area with hard water to one with softer water. Previously, my hair felt rough, dry, and frizzy after a . Now, with the softer water, my hair is smoother, more manageable, and less frizzy.
It turns out, the quality of water plays a big role in how healthy and shiny your hair is. The amount of calcium in your water can significantly impact your hair's health. Asun Pont, a trainer at Kérastase Spain, explains that hard water can make hair rough, brittle, and harder to manage.
“Hair tends to become visibly rougher and more brittle, difficult to comb, and stiffer to the touch. In addition, movement is reduced, which means a lack of vitality in the overall mane,” she says. Bleached, coloured, or straightened hair is particularly vulnerable to damage.
Pont explains that frequent use of heat tools can make hair more porous and prone to wear and tear. "In addition to styling tools, factors like exposure to free radicals and seasonal elements, such as sun and pool chemicals, also impact hair health," she says. Calcium in hard water further exacerbates hair weakness.
However, she notes that proper decalcification can help mitigate this damage. Calcium in water can lead to notably dehydrated hair. "This can cause hair to tangle more easily and slow its because of increased split ends and breakage in the more delicate areas," explains the .
Ultimately, it results in dull, lacklustre hair that's more susceptible to external factors like humidity. “If you notice your or skin feeling dry after a shower, it might be due to hard water with high lime content,” warns Pont. To check if your water has too much limescale, look at your faucets and sink.
If you see white spots after they dry, it's a sign of high limescale levels. To counteract the negative effects of calcium in the water used for washing hair, it’s essential to maintain a healthy hair care that includes both repair and decalcification. This can be achieved through salon treatments or specific home products.
For instance, the Kérastase Première range offers both repairing and decalcifying benefits. It helps remove excess limescale from the most delicate areas of the hair and strengthens weak spots, ensuring that water quality doesn’t compromise your hair's vitality. Pont recommends performing decalcification at least once a week if you have hard water at .
"It is a way for the hair not to lose proteins or lipids that are necessary for a healthy mane," she says. Shop hair products below.
