Although drinking hard water is harmless, hard water and skin do not mix well. The former can cause irritation, itching and skin and scalp disorders.

Hard water and tight skin

The public health code requires water distribution companies not to deliver harmful or corrosive water, but does not specify its hardness. Depending particularly on the area where you live, your water has a greater or lesser degree of hardness, occasionally with consequences for your skin. A shower with hard water (and a bath) frequently results in tight or prickly skin and coarse, dull and brittle hair.

Skin reactions due to hard water

This observation holds particularly true for children and people with sensitive skin. Mineral crystals in hard water, invisible to the naked eye, prickle the skin, producing an unpleasant sensation and covering it with a drying layer. Subjected to these adverse effects, skin occasionally reacts with the appearance of small spots or stinging scales: in short, skin disorders.

Hard water may be a factor contributing to psoriasis and eczema or dermatitis. On sensitive skin it can even cause desquamation, i.e. peeling of the surface skin layer. Similarly, by causing a dry scalp, hard water can cause itching on the head. People suffering from psoriasis are therefore advised not to wash with hard water. In addition, all these phenomena can be aggravated by the use of certain shampoos and soaps.

Softening hard water in the bathroom

Without tripling your use of moisturising creams, the effects of hard water on the skin can be countered at source by fitting a water softener. It will filter out the crystals mentioned above which cause irritation and itching. There are very simple water softening systems. A limescale filter can for example be fitted between the tap fittings and the flexible shower hose, while other filters can be placed under the tap in the bath. In the first case, the filter is equipped with a cartridge which is changed about once a year.

By reducing water hardness, filter systems provide softened water for washing, with no ill-effects on the skin and the scalp. Another advantage of this equipment is that it prevents the tap and shower head from accumulating limescale, ensuring a stronger flow rate and water savings. An independent American study by the Battelle Memorial Institute in Illinois demonstrated in 2009 that as a result of limescale accumulation “the flow rate in shower heads dropped by 75% in less than 18 months when used with hard water".