Water hardness refers to the amount of dissolved minerals, primarily calcium and magnesium, found in water. These minerals are naturally acquired as water travels through various geological formations. Understanding water hardness is important because its mineral content influences how water interacts with plumbing, appliances, and personal care routines, affecting many aspects of daily life.
Understanding Water Hardness
Water hardness is determined by the concentration of dissolved calcium and magnesium ions. As rainwater percolates through underground deposits like limestone, it dissolves these minerals, carrying them into the water supply. It is commonly measured in grains per gallon (GPG) or parts per million (PPM), which is equivalent to milligrams per liter (mg/L). One GPG equals approximately 17.1 PPM.
Water is classified into categories based on these measurements. For example, water under 60 mg/L (3.5 GPG) is soft, while over 180 mg/L (10.5 GPG) is very hard. Hardness can be temporary or permanent. Temporary hardness, caused by bicarbonates, can be reduced by boiling. Permanent hardness, due to sulfates and chlorides, is not removed by boiling.
Impacts on Household and Daily Life
Hard water causes issues for appliances and cleaning. Mineral deposits, or limescale, build up inside pipes and water-using appliances like water heaters and dishwashers. This accumulation reduces appliance efficiency, forcing them to work harder and shortening their lifespan by 30-50%. Limescale in water heaters, for instance, acts as an insulating layer, increasing energy consumption as the heating element struggles to transfer heat.
Cleaning tasks are more challenging with hard water. Minerals react with soaps and detergents, inhibiting lather. This forms soap scum, an insoluble residue that clings to surfaces. More soap or detergent is needed for cleanliness, increasing household expenses. Dishes and glassware may show white spots or a cloudy film, and clothes can feel stiff or appear dull.
Hard Water and Human Health
Hard water is safe for drinking and does not pose health risks. Its calcium and magnesium minerals can contribute a small amount to daily mineral intake. While some studies suggest positive effects on cardiovascular health, water is not a primary source for most dietary mineral needs.
Hard water can affect skin and hair. Dissolved minerals leave a residue on the skin, contributing to dryness, irritation, or an itchy sensation. This mineral film can prevent natural oils from reaching the skin’s surface and may exacerbate conditions like eczema. Hair washed with hard water may feel dull, dry, or difficult to manage due to mineral buildup, leading to less effective rinsing of shampoos and conditioners.