Blueberries like a lower pH level, typically a pH range of 4.5 - 5.5 is ideal for blueberries. Sulphur lowers the soils pH level making it an ideal soil amendment for your blueberries. To test your pH level, us a pH tester. If you do not have one, you may click here to purchase one from us. This is 1lb. of Sulphur.