For sequential determination of Calcium and Total Hardness by EDTA Digital Titrator titration. Hach method 8329. Range: 100 - 4000 mg/L CaCO3. Set contains Buffer Solution (Hardness 1), CalVer2 Calcium Indicator Powder Pillows, ManVer2 Hardness Indicator Powder Pillows, Potassium Hydroxide Solution (8 N), Sulfuric Acid (5.25 N) and 0.800 M EDTA Digital Titrator Cartridge. Approximately 40 - 100 tests.