pH/EC/TDS Meters

Controlling the pH in your hydroponic system allows the plants to consume a broader range of nutrients and other elements. What does that lead to? Bigger, tastier, more beautiful and more aromatic plants. Controlling the TDS leads to tastier plants and prevents under/over feeding.

Not sure what PPM scale to use? It depends on your nutrients. Click here to figure out which PPM scale you should use.

To view our selection of pH adjusters (pH up and pH down), click here.

1 - 60 of 65 items
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Bluelab pH Pen Bluelab ppm Pen Bluelab Growers Toolbox
Bluelab pH PenBluelab ppm PenBluelab Growers Toolbox

The ultimate handy solution for measuring pH and temperature.

The ultimate handy solution for measuring conductivity (ppm) and temperature!

Includes both pH and ppm pens with probe care kit

$112.50

$99.99

$93.95

$83.99

$198.95

$174.99

Bluelab Truncheon (Low Range) Bluelab Commercial Truncheon (Broad Range) Bluelab pH Meter
Bluelab Truncheon (Low Range)Bluelab Commercial Truncheon (Broad Range)Bluelab pH Meter with Probe

Extremely reliable, durable, handy conductivity meter - low range.

Extremely reliable, durable, handy conductivity meter - broad range.

Lightweight, portable, accurate, handheld, digital pH meter with probe.

$139.95

$125.99

$139.95

$125.99

$209.95

$189.99

Bluelab Guardian Monitor Bluelab Combo Meter Bluelab pH Controller
Bluelab Guardian MonitorBluelab Combo MeterBluelab pH Controller

The simplest reservoir monitor you could ever own. Continuous reading of pH, EC and Temperature.

Very reliable; conductivity, pH and temperature - all in one meter!

Hands-free monitoring and adjusting of solution pH levels

$398.95

$359.99

$298.95

$269.99

$568.95

$489.99

Bluelab pH Controller - Connect Bluelab Soil pH Pen Bluelab Soil pH Meter
Bluelab pH Controller - ConnectBluelab Soil pH PenBluelab Soil pH Meter

Hands-free monitoring, adjusting and data logging of solution pH levels

Accurate soil pH measuring made simple! Measures pH in soil and liquid.

Accurate soil pH measuring made simple! Measures pH in soil and liquid.

$628.95

$499.99

$184.95

$169.99

$239.95

$218.99

Bluelab Meter Carry Case Bluelab Connect Stick Bluelab Connect Range Extender
Bluelab Meter Carry CaseBluelab Connect StickBluelab Connect Range Extender

Makes transporting and using Bluelab handheld meters even easier!

Allows the Bluelab Guardian Monitor and pH Controller to be viewed online/ on mobile device

Extends wireless range between Guardian Connect and Connect Stick

$24.95

$23.19

$149.95

$134.99

$163.95

$146.99

Milwaukee pH600 pH Meter With 1 Point Manual Calibration Milwaukee Waterproof PH Tester Milwaukee T75 Waterproof TDS Tester (Low Range)
Milwaukee pH600 pH Meter With 1 Point Manual CalibrationMilwaukee pH55 Waterproof PH TesterMilwaukee T75 Waterproof TDS Tester (Low Range)

Economical, pocket pH tester.

Pocket-size pH / temperature meter with replaceable electrode

Waterproof TDS meter with replaceable electrode (low range).

$32.95

$31.99

$85.95

$76.99

$88.95

$79.99

Milwaukee T76 Waterproof TDS Tester (High Range) Milwaukee pH hand meter SM101 Milwaukee MW802 Portable pH, Conductivity, TDS Combination Meter
Milwaukee T76 Waterproof TDS Tester (High Range)Milwaukee MW101 Portable pH Meter with 0.01 pH ResolutionMilwaukee MW802 Portable pH, Conductivity, TDS Combination Meter

Waterproof TDS meter with replaceable electrode (high range).

Portable pH meter with 0.01 pH resolution.

Standard portable pH / conductivity / TDS combination meter

$88.95

$79.99

$132.95

$119.99

$256.95

$233.99

Milwaukee AG900 Portable pH, EC, TDS Combination Meter Kit Milwaukee M600 Dissolved Oxygen Meter Nutradip AC/DC PPM/EC Meter
Milwaukee AG900 Portable pH, EC, TDS Combination Meter KitMilwaukee M600 Dissolved Oxygen MeterNutradip AC/DC PPM/EC Meter

Excellent for measuring pH in soil and liquids.

Simple, easy-to-use dissolved oxygen meter.

AC and DC powered ppm/EC meter.

$354.95

$299.99

$301.95

$273.99

$119.95

$107.99

Hanna Primo TDS Tester Hanna HI98107 pHep pH Tester Hanna HI98301 DiST 1 TDS Tester
Hanna Primo TDS TesterHanna HI98107 pHep pH TesterHanna HI98301 DiST 1 TDS Tester

Fast and dependable way to measure the total dissolved solids in your water samples.

With 2 point calibration for accurate pH measurement.

Pocket TDS tester with 1 mg/L resolution and 0.5 TDS factor.

$55.95

$51.99

$55.95

$51.99

$73.95

$66.99

Hanna HI98311 DiST 5 EC/TDS/Temperature Tester - Low Range Hanna pHep 4 pH/Temperature Tester with 0.1 pH Resolution Hanna pHep 5 pH/Temperature Tester with 0.01 pH Resolution
Hanna HI98311 DiST 5 EC/TDS/Temperature Tester - Low RangeHanna pHep 4 pH/Temperature Tester with 0.1 pH ResolutionHanna pHep 5 pH/Temperature Tester with 0.01 pH Resolution

Pocket TDS tester with 1 mg/L resolution and 0.5 TDS factor - for low range measurements.

Broad range pH meter with 0.1 pH resolution.

Broad range pH meter with 0.01 pH resolution.

$140.95

$126.99

$126.95

$113.99

$139.95

$125.99

Hanna HI98129 Combo pH/EC/TDS/Temperature Meter Hanna HI98130 pH/Conductivity/TDS Pocket Tester - High Range Hanna HI9811-5N Portable pH/EC/TDS/Temperature Meter
Hanna HI98129 Combo pH/EC/TDS/Temperature MeterHanna HI98130 pH/Conductivity/TDS Pocket Tester - High RangeHanna HI9811-5N Portable pH/EC/TDS/Temperature Meter

This waterproof all-in-one meter measures pH, EC, TDS, and temperature.

Poprtable pH/Conductivity/TDS meter with high range EC measurement.

Portable pH/EC/TDS/Temperature meter (low range EC & TDS).

$213.95

$194.99

$213.95

$194.99

$285.95

$259.99

Hanna HI9813-6 Portable pH/EC/TDS/Temperature Meter w/ Cal Check Hanna HI981401N-01 GroChek Water Resistant pH Indicator Hanna HI981404N-01 pH & TDS Continuous Reading Indicator
Hanna HI9813-6 Portable pH/EC/TDS/Temperature Meter w/ Cal CheckHanna HI981401N-01 GroChek Water Resistant pH IndicatorHanna HI981404N-01 pH & TDS Continuous Reading Indicator

Portable, reliable combination meter with automatic calibration checking feature.

Durable, water resistant pH indicator.

Monitors and displays pH and TDS levels for optimal plant growth.

$292.95

$266.99

$156.95

$139.99

$249.95

$229.99

Hanna HI981504-5 Continuous pH/TDS/temp Monitor - 1382 ppm Hanna HI981504-7 Continuous pH/TDS/temp Monitor - 1500 ppm Hanna HI991404-01 GroChek pH/EC/TDS/Temp. Monitor - Low Range
Hanna HI981504-5 Continuous pH/TDS/Temp Monitor - 1382 ppmHanna HI981504-7 Continuous pH/TDS/Temp Monitor - 1500 ppmHanna HI991404-01 GroChek pH/EC/TDS/Temp. Monitor - Low Range

Continuous pH/TDS/temperature monitor - 1382 ppm.

Continuous pH/TDS/temperature monitor 1500 ppm

Continuously monitors pH, EC, TDS and temperature.

$299.95

$272.99

$299.95

$272.99

$278.95

$253.99

Hanna HI993310 Soil Activity and Solution Conductivity Meter Kit Hanna BL981411 Automatic Mini pH Controller 115v AC Hanna BL981411-0 Automatic Mini pH Controller 12v DC
Hanna HI993310 Soil Activity and Solution Conductivity Meter KitHanna BL981411 Automatic Mini pH Controller 115v ACHanna BL981411-0 Automatic Mini pH Controller 12v DC

Direct soil activity and solution conductivity meter with carrying case.

Automatic pH controller - runs on standard AC power.

Automatic pH controller - runs on DC power.

$769.95

$689.99

$235.95

$221.99

$235.95

$199.99

HydroLogic TDS Pro - In/Out PPM Monitor HM Digital TDS-3 Handheld TDS/Temperature Meter HM Digital AP-1 AquaPro Water Quality Tester (TDS)
HydroLogic TDS Pro - In/Out PPM MonitorHM Digital TDS-3 Handheld TDS/Temperature MeterHM Digital AP-1 AquaPro Water Quality Tester (TDS)

Measures the untreated water coming in vs. the purified water going out of your Reverse Osmosis system.

Handheld TDS meter with case.

Handheld TDS and temperature meter.

$74.95

$67.99

$36.95

$34.39

$42.95

$39.99

HM Digital COM-80 EC/TDS/Temperature Water Resistant HydroTester HM Digital COM-100 Waterproof EC/TDS/Salinity/Temperature Meter HM Digital PH-80 PH/Temperature Water Resistant HydroTester
HM Digital COM-80 EC/TDS/Temperature Water Resistant HydroTesterHM Digital COM-100 Waterproof EC/TDS/Salinity/Temperature MeterHM Digital PH-80 PH/Temperature Water Resistant HydroTester

Measures electrical conductivity (EC), total dissolved solids (TDS) and temperature.

Measures electrical conductivity (EC), total dissolved solids (TDS), salinity and temperature.

Water resistant pH and temperature meter.

$42.95

$39.99

$76.95

$71.99

$46.49

$41.99

HM Digital PH-200 Waterproof pH/Temperature Meter Oakton Waterproof ECTestr 11 Oakton Waterproof ECTestr 11+
HM Digital PH-200 Waterproof pH/Temperature MeterOakton Waterproof ECTestr 11Oakton Waterproof ECTestr 11+

Waterproof pH/temperature meter suitable for many applications.

Dual range to cover a wide range of applications.

Three ranges for maximum resolution.

$99.95

$89.99

$127.95

$114.99

$169.95

$151.99

Oakton Waterproof Double Junction pHTestr 30 Oakton Waterproof Multiparameter PC Testr 35 (EC & pH) Autopilot Digital Automatic pH Controller
Oakton Waterproof Double Junction pHTestr 30Oakton Waterproof Multiparameter PC Testr 35 (EC & pH)Autopilot Digital Automatic pH Controller

Broad range pH meter; dual display of pH and temperature.

Measure pH and conductivity in one easy-to-use meter.

Automatically maintains proper pH

$176.95

$158.99

$206.95

$181.99

$369.95

$332.99

Rapitest Digital PLUS Soil pH Meter Active Air Gardener's 2 Way Meter (pH & Moisture) Active Air Gardener's 3 Way Meter (pH, Moisture & Light)
Rapitest Digital PLUS Soil pH MeterActive Air Gardener's 2 Way Meter (pH & Moisture)Active Air Gardener's 3 Way Meter (pH, Moisture & Light)

Includes a built-in database of pH for many types of plants.

Measures moisture and pH.

Measures moisture, light and pH.

$28.95

$27.49

$7.95

$6.99

$9.95

$8.99

Rapitest Soil Test Kit (pH, Nitrogen, Phosphorous and Potash) General Hydroponics Complete pH Control Kit General Hydroponics pH Test Kit 1 oz
Rapitest Soil Test Kit (pH, Nitrogen, Phosphorous and Potash)General Hydroponics Complete pH Control KitGeneral Hydroponics pH Test Kit 1 oz

Quick and easy way to test pH, Nitrogen, Phosphorous and Potash levels in soil. 

Everything you need to test and adjust pH.

Includes 1 oz of pH test indicator and one test vial.

$17.95

$16.49

$17.99

$17.09

$7.54

$7.19

1 - 60 of 65 items