R-0718 is the second of 2 reagents used in the test for sodium chloride. R-0630 is added to 10mL of pool water to produce a color change to yellow. Then, R-718 Silver Nitrate Reagent is added drop by drop to produce a color change to milky red ("salmon color"). The required number of drops is multiplied by 200 to determine salt levels in ppm. This bottle contains 0.75oz, enough for 80+ tests.
Please note that this reagent's "Best By" date is shorter than all other reagents. However, TFtestkits still guarantees this reagent for 1 year from purchase.