Hydrofarm Black and White Poly APCEM2 Meters can be recalibrated with

Meters can be recalibrated with a mini-screwdriver

UL-listed NOTE: Models 40 GPH-160 GPH contain a steel shaft and are not suitable for saltwater applications

5 to 75 mL/gal) [D14MZ2VFBPHY]

high-quality

Hydrofarm Black and White Poly APCEM2 Meters can be recalibrated withGet double the grow room assistance with this waterproof alternative to metalized film. Unroll this two sided film and custom fit your indoor garden, eliminating concerns over whether you've got afternoon facing light or a climate that supports your preferred greenery. Use the white side for walls and floors, taking advantage of the material's 90 percent reflectivity. When you want to block out light and sun, use the light resistant black side. Adding