The term “water hardness” originally referred to the ability of water to precipitate soap and form soap scum. Soap is precipitated, or brought to the surface, by water containing high levels of calcium and magnesium. The “harder” the water, the less soap will dissolve in it.
In current practice, total hardness is defined as the sum of the concentration of calcium and magnesium ions, expressed as calcium carbonate. Read More
Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. The word tannin refers to the source of tannins used in tanning animal hides into leather; however, the term is widely used to refer to brown color in water caused by decaying organic substances.Read More