Total Hardness Test Kit (Powder Indicator). 1 drop=2 or 10ppm as CaCO3/25ml. Reagents Included: HZED2070-B, Hardness Titrant High, 60ml; HZED2073-B, Hardness Titrant Low, 60ml; HZHA7405-A, Hardness Buffer, 30ml; HZHA7475-H, Hardness Indicator Powder, 10g.