Kwantum antiscalent forms film on the inner surface of the pipeline or coil shell etc. E.g. If water contains camg carbonate then it converts in to a phosphate which remains in colloidal stage and afterwards settles at the bottom of container from where it is being pumped. Over a period of time the sludge has to be drained out which is also called as blow down of the stagnant water. Phosphate in circulating water that to be maintained in +ve stage