Use settling cones and rack to determine settleable materials in water and wastewater samples, and sand in well water. Cones are externally graduated in mL from the bottom upward: lines at 0.3 and 0.4 mL, 0.5 to 1 mL in 0.1 mL increments, 1 to 10 mL in 0.5 mL increments, 10 to 40 mL in 1 mL increments, 40 to 100 mL in 2 mL increments, and then lines at 250, 500 and 1000 mL.