Hydroponics Grow Nutra Wand Nutrient Test Lab Meter Pen Tester,EC/PPM/CF

280 ~ 3080 ppm ( x 700). 200 ~ 2200 ppm ( x 500). 70 ppm (700 conversion factor). 50 ppm (500 conversion factor). Place the probe back into the solution. The lights will indicate the nutrient levels.

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