Gardeners can conveniently test their moisture, light and pH levels with the handy Active Air 3-Way Meter. Moisture readings register on a scale of 0 (dry) to 10 (moist) light readings range from 0 (low light) to 2000 (very strong light) accurate pH readings range between pH 4 and 8. Remove from soil and clean prongs after each use to ensure the moisture meter stays in top performance shape.