The HI736-25 are the replacement reagents for the HI736 Phosphorus Ultra Low Range Checker® HC. These high-quality reagents are manufactured in our state-of-the-art facility and are clearly marked with the lot number and expiration date on each packet for traceability.Features: Pre-made reagents for ease of use Prepared with high purity chemicals Marked with expiration date and lot number for traceabilitySpecifications:PackageSachetsQuantity25MethodAdaptation of the Standard Methods for the Examination of Water and Wastewater, 20th edition, Ascorbic Acid method. The reaction between phosphorus and the reagent causes a blue tint in the sample.For use with Hanna Instruments Checker Marine Ultra Low Range Phosphate Colorimeter HI736