Hard water contains a lot of calcium, magnesium and other minerals. Groundwater acquires these minerals by dissolving them from surrounding soil and rock. Water treatment plants measure water hardness in terms of grains per gallon (GPG ). How can hard water affect you? Hard water causes two problems. Dissolved calcium and magnesium precipitate out of hard water as scale, which builds up on the insides of pipes, water heaters, tea kettles, coffee makers and industrial machinery. Scale reduces water flow through pipes and is a poor conductor of heat. Eventually your pipes can become completely clogged. Hard water reduces soap’s ability to lather, rather in the shower, sink, dishwasher or washing machine and reacts with soap to form a sticky scum. You can combat hard water by adding powdered borax to your water or by running it through a water softener.