Several polyphosphate treatments have been tried mainly for treating the rust problem. The most cost effective treatment for our system at this time is a 2 to 5 ppm dosage of sodium tripolyphosphate (food grade). It is adjusted in this range depending on the iron content of the raw water. This chemical acts to sequester or "tie up" the iron in its bivalent, clear and soluble state. Time and warm temperature have a tendency to render this treatment wretchedly temporary. Polyphosphates also act to reduce corrosion, scaling and leaching of lead. Back to Contents
Edited 02/07/2004