The Aquaness ARQUEST™ 6113 scale inhibitor is a (ATMP) phosphonic acid developed for scale inhibitor formulations. This product is supplied as an un-neutralized organic acid for preparation of neutral salts by the formulator. Polyethylene-lined drums are required for storage and shipment. When neutralized to a pH of 7.0 to 8.0, ARQUEST 6113 scale inhibitor becomes a powerful chelant, requiring epoxy-phenolic-lined drums. Phosphonates made with this product will provide scale inhibition at concentrations of 0.5 to 3.0 ppm of product for both calcium sulfate and calcium carbonate scale. Because of its excellent thermal stability, phosphonates are used successfully at temperatures in excess of 250°F (121°C). Formation squeeze applications may be performed with the neat or neutralized form. In the presence of limestone, ARQUEST 6113 scale inhibitor will precipitate as a slightly soluble calcium salt. Ion exchange with calcium-bearing formations will occur along with surface adsorption of the phosphonate. “Returns” or phosphate residuals may be measured by oxidizing the phosphonate to orthophosphate and proceeding with the standard colorimetric determination. Formulate ARQUEST 6113 scale inhibitor to a fi nished product by blending 10 to 20% in a water and ethylene glycol solution then neutralize with sodium hydroxide to pH 7.0 to 8.0. For some high TDS systems, products formulated to lower pH (3 to 5) or un-neutralized will have improved solubility. Ethylene glycol may be