Determination of Biochemical Oxygen Demand (BOD5)

3. Dilution water may be prepared immediately before use, or, except for the addition of the phosphate buffer, days or weeks ahead of time. Add 1 ml or each nutrient solution per liter of dilution water. The phosphate buffer is the critical nutrient in stimulating contaminating growths so it must be added the day the water is to be used. ................
................