Water is Nature's most Wonderful, most abundant, useful compound. It is estimated that 2/3 rd of the human body constitutes of Water. It also occupies a unique position in industries. It has a very important use as an engineering in stem generation. Water is also used as a coolant in power and chemical plants. Water is very complex in nature. It contains a lot of impurities in dissolved & suspended form. The calcium & magnesium salts present in the water determines the hardness of water. It is this hardness of water which is of concern for scale problems in industries.