The HI93717-01 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. The method is an adaptation of the Standard Methods for the Examination of Water and Wastewater, 18^th edition, Amino Acid method. The reaction between phosphate and reagents causes a blue tint in the sample. By simply adding the reagents to the sample, a reaction will take place and a compatible benchtop or portable meter can be used to determine the concentration from the color that is produced. The results will be displayed in mg/L (ppm) of phosphate (PO₄^3-). These reagents are designed to be used with samples that have an expected range of 0.0 to 30.0 mg/L phosphate.