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 LUX (low light) to 2000 LUXÂ (very strong light). accurate pH readings range between pHÂ 3.5 and 8. The durable, easy-to-read tester is suitable for indoors or out and needs no batteries to operate. Remove from soil and clean prongs after each use to ensure the moisture meter stays in top performance shape."