1. Remove any obstruction to the soil that requires testing, such as surface soil, grass, leaves,pebbles, etc. If the soil is dry or contains too much fertilizer, sprinkle some water onto the soil and leave for 25-30 minutes before testing 2. Before using the tester, be sure to thoroughly clean its metallic surface with a piece of whetting cloth. When using a brand-new tester, we advise you to ...