Silicate (Silicic Acid) Test Method: colorimetric with color card and comparator block with long test tubes 0.01-0.02-0.04-0.06-0.08-0.10-0.15-0.20-0.25 mg/l Si 0.02-0.04-0.09-0.13-0.17-0.21-0.32-0.43-0.53 mg/l SiO₂ MColortest™