The HI706-25 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate measurements with their Phosphorus High Range Checker^® HC. These reagents follow the Amino Acid Method in which the reaction between phosphorus and reagents causes a blue tint in the sample. By simply adding 10 drops of the first reagent to the sample, followed by the packet of the HI706-25 reagent set, the reaction will take place and the HI706 will determine the concentration from the color that is produced. The results will be displayed in ppm (mg/L) of phosphorus. These reagents are designed to be used with samples that have an expected range of 0.00 to 15.00 ppm (mg/L) phosphorus.