Bluelab Combo MeterIt s all you need for simple and reliable crop management. The Bluelab Combo Meter is a portable pH, conductivity and temperature meter all in one. If you are experiencing problems with yellow leaves, or slow stunted growth, the Bluelab Combo Meter will soon tell you if each parameter is within the plants requirements. Adjustments can be quickly made to get your crop back on track. The Bluelab Combo Meter has two probes, a Bluelab pH Probe and a