HM Digital COM-100 HMDCOM100 Waterproof EC/TDS And Amp Temperature Combo Meter, 2.1" x 2.9" x 8.9", White/Purple

ZeroWater ZT-2 Electronic Water Tester, Blue

HM Digital AP-1 AquaPro Water Quality Total Dissolved Solids Tester, 0-5000 ppm TDS Range, 1 ppm Resolution, +/- 2% Readout Accuracy (Magnetic Body)

Commercial In-Line Dual TDS Monitor

HM Com 100 and PH 200

HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume

HM Digital PH-200 Waterproof Temperature PH Meter, 3.3" x 8.5" x 2", White

HM Digital 1000ppm TDS Calibration Solution

Apera AI209-T Value Series PH20 pH Tester Combo Kit with 8 oz. Calibration buffers (4,7,10), 4 oz. 3M KCL Storage Solution, Probe Cleaning Brush & CalPod Solution Holder for Easy Calibration

HM Digital 716160 COM-100 WATERPROOF PROFESSIONAL SERIES Combo Meter, 7", White/Purple

HM Digital PH-STOR pH Electrode Storage Solution for Use with PH-200 or PH-80, 60cc Volume

General Hydroponics Ph 7.0 Calibration Solution - 8 Ounces, 1 bottle

Great White PRPSGW04 100049823 4 oz Mycorrhizae, 4 Ounce

VIVOSUN Retractable Plant Yoyo with Stopper for Grow Support in Tent Garden or Hydroponics, Pack of 12

General Hydroponics 722080 pH Control Kit for A Balanced Nutrient Solution