However, the laboratory report usually lists hardness as equivalent calcium carbonate. Hard water, when heated, develops hard scale on pipes, cooking utensils, and other metal objects. The life and efficiency of heating equipment are decreased by the production of the hard scale on heating coils or element. Hard water causes soaps to curd in the water rather than make a lather. Dissolved Gas Dissolved gases usually are carbon dioxide and hydrogen sulfide.
Carbon dioxide results primarily from decaying organic matter in water-bearing soils.
It accelerates corrosion of iron, brass, copper, and aluminum, causing rust-colored stains from copper piping. Hydrogen sulfide comes from a sulfur source, usually accompanies iron in water, and releases a rotten-egg odor. Hydrogen sulfide corrodes iron, brass, and copper and causes black stains. Metallic taste often results from the corrosion of plumbing. Acidity Normally the pH of the water is 7 to 7.5.