GAIN EXPRESS 2-in-1 PH and Temperature Monitor, PH Measuring Instrument, PH Meter, Measuring Range 0-14 pH, Water Quality Measurement, Aquarium, Hydroponics, Backlight Function, Replaceable

2 in 1 pH & Temperature Monitor, pH Meter with Backlight Function, Dual Display 0.00~14.00pH °C/ °F Water Quality Tester pH Monitor for Water, Fish Tank, Aquarium, Hydroponics, Pools

General Hydroponics pH Control Kit For A Balanced Nutrient Solution

VIVOSUN Digital pH and TDS Meter Kits, 0.01pH High Accuracy Pen Type pH Meter ± 2% Readout Accuracy 3-in-1 TDS EC Temperature Meter for Hydroponics, Pool and Aquarium, Yellow Blue, UL Certified