1: This soil meter CAN ONLY be used in soil. DO NOT use it to test any liquids directly, such as pure water, lemon juice, vinegar and so on, or the probes may be damaged
2: DO NOT insert the soil meter into very hard soil or touch hard objects, easy to damage the probes
3: This soil meter cannot accurately gauge the intensity of grow lights because most light bulbs lack the full spectral range of sunlight. To maximize the accuracy of sunlight readings, point the light sensor at the top front of the meter toward the sun
4: DO NOT leave the probes inserted in the soil longer than necessary to make a measurement