Apera Instruments
Apera Instruments PH20 pH Tester Kit
Waterproof pocket pH tester kit with automatic calibration and a replaceable probe — the budget benchmark for pH.
Show dealMeters & Testing — deals & promo codes
58 grower deals in Meters & Testing, each one linking straight to the seller for that deal — seed banks for seeds, Amazon (with our tag) for gear. Updated from checks dated Oct 2026.
Bluelab
Bluelab pH Pen
The hydro-shop standard: fully waterproof, backlit display, double-junction probe and auto-off to save the battery.
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Bluelab
Bluelab PENCON Conductivity (EC) Pen
Conductivity pen measuring EC, CF and ppm in 500/700 scales — fully waterproof with a backlit display.
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HM Digital
HM Digital COM-80 EC/TDS Meter
Waterproof meter that reads EC, TDS and temperature with auto-calibration — a tough, affordable combo meter.
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Amazon
Apera PH20 pH Pen — Waterproof, Auto Calibration
The step-up pH pen: replaceable probe, two-point auto calibration, genuinely waterproof.
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Amazon
Apera EC20 Conductivity Pocket Tester
The EC twin of the PH20 — matched pair for feed mixing in under a minute.
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Amazon
Milwaukee PH600 Digital pH Pen
Budget pH pen with manual calibration — the gateway meter that beats drops and strips.
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Amazon
5-in-1 Water Quality Meter — pH, TDS, EC, Salinity, Temp
One pen for the whole mix: pH, EC/TDS, salinity and temperature with ATC.
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Amazon
HM Digital TDS-3 Meter with Case
The classic quick TDS check for RO output and reservoir drift.
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Amazon
Soil Meter 3-in-1 — Moisture, pH, Light (No Battery)
Analog probe for outdoor beds and houseplants. No batteries, instant moisture reads.
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Amazon
Soil Moisture Meter XL — 12 in Probe, Battery Included
Deep probe for big pots and beds — check the bottom of the root zone, not just the crust.
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Amazon
Quantum PAR Meter — Full Spectrum LED Ready
Measure actual light (PPFD) at canopy height and stop guessing about distance and dimmers.
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Amazon
Digital Lux Meter — 0.1 to 200,000 Lux
Budget light meter for comparing corners and shelves. Convert to PPFD with a known factor.
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Amazon
CO2 Meter Portable — NDIR with Alarm
Handheld CO2 reader for sealed rooms, greenhouses and mushroom corners.
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Amazon
Govee-Style Bluetooth Thermo-Hygrometer — 2 Pack
App-logging sensors for tent and dry room. Alerts when VPD conditions drift out.
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Amazon
Inkbird IBS-TH2 Bluetooth Sensor
Tiny logging sensor that lives in a jar, tent or dry box and graphs the whole cure.
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Amazon
Thermometer Hygrometer with Probe — Min/Max
Wired probe reads inside the tent while the display sits outside. Min/max memory included.
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Amazon
ORP Meter Pocket — for Water Sanitation Checks
Check sanitizer strength in wash water and system flushes by oxidation-reduction potential.
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Amazon
Chlorine Test Strips — 100 Count
Verify dechlorination before watering living soil or filling humidifiers.
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Amazon
pH Test Strips Wide Range 1-14 — 100 Count
Backup pH checks that never need calibration — keep a vial in every room.
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Amazon
pH Calibration Solution Kit — 4.0, 7.0, 10.0 Packets (20 Each)
Single-use calibration packets — fresh solution is the difference between readings and guesses.
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Amazon
pH Probe Storage Solution — 250 ml
Keep pen probes hydrated in storage so they stay fast and accurate.
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Amazon
EC Calibration Solution 1413 — 250 ml
Standard 1413 uS solution for conductivity pens. Calibrate monthly, trust your feed.
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Amazon
Refractometer for Brix — 0-32% with ATC
Measure plant sap and fruit sugar — a health and ripeness gauge for serious gardeners.
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Amazon
Infrared Thermometer Gun — Laser, -58 to 1022F
Leaf-surface temperature in one trigger pull — the VPD number that actually matters.
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Amazon
Leaf Thermometer Clip — IR Mini for Canopy
Clip-on spot checker for quick canopy temperature rounds.
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Amazon
Waterproof Thermometer for Reservoirs — Floating
Floating reads for DWC buckets and reservoirs — roots like 65-68F, know yours.
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Amazon
Light Cycle Data Logger — USB, 90 Day
Logs light and temperature — prove your dark cycle is dark and your room is steady.
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Amazon
Multimeter for Growers — Voltage, Continuity, Outlet Test Kit
Chase the tripped circuit and dead outlet yourself: meter, tester and leads in one kit.
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Amazon
Kill-A-Watt Style Electricity Monitor
See what each light and fan actually costs to run, per day, in dollars.
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Amazon
Analog Min/Max Greenhouse Thermometer — Wall Mount
No batteries, no app — the high/low since you last reset it, at a glance.
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Amazon
Bluelab Guardian Monitor — pH, EC, Temperature Wall Unit
Wall monitor that watches pH/EC/temp 24/7 with big digits — the reservoir's dashboard.
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Amazon
Bluelab Truncheon EC Meter — Commercial
The indestructible EC wand every hydro shop owns — dip, read the flashing lights, done.
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Amazon
Bluelab Combo Meter Plus — pH and EC in One
Two probes, one meter — the Bluelab step up from pens for daily mixing.
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Amazon
Apera GroStar GS1 pH Pen — Grower Series
GroStar pH pen with a flat/soil-friendly probe option — built for nutrient mixing.
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Amazon
Apera GroStar GS2 EC Pen — Grower Series
The EC half of the GroStar pair — matched design, replaceable probe.
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Amazon
Hanna GroLine pH Tester HI98118 — Waterproof
Hanna's grower pH pen with a renewable junction — hydro-store counter classic.
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Amazon
Hanna Soil EC Tester HI98331 — Direct Soil Probe
Stick it in the root zone — direct soil EC without slurry tests.
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Amazon
Milwaukee MW802 Combo Meter — pH, EC, TDS
Bench/portable combo with separate probes — one unit for the whole mix station.
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Amazon
Oakton EcoTestr pH 2+ Pocket Meter
Waterproof pocket pH with double-junction probe — lasts longer in fertilizer solutions.
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Amazon
SensorPush HT1 Temperature and Humidity Sensor
Tiny pro-grade logging sensor with a serious app — alerts for tent, dry room and jars.
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Amazon
Elitech Temperature Data Logger — USB, Refrigerator Grade
Cold-chain logger that graphs a whole dry/cure — plug into USB, get the PDF.
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Amazon
ThermoPro TP62 Bluetooth Hygrometer Station
Bluetooth thermo-hygrometer with app history — the lounge-chair way to check the tent.
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Amazon
AcuRite Greenhouse Thermometer with Humidity — Analog Dial
Big-dial analog station for the greenhouse wall — no batteries, always on.
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Amazon
SpotOn Quantum PAR Sensor — Handheld
Dedicated quantum sensor with a cosine-corrected head — PPFD readings you can trust.
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Amazon
Apogee MQ-500 Full-Spectrum Quantum Meter
The research-grade PAR meter — the number other meters get compared against.
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Amazon
Hydrofarm PAR Meter — LED Ready Quantum Sensor
Grower-priced PAR meter tuned for LED spectrums.
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Amazon
RAD-0002 CO2 Meter — Desktop NDIR with Alarm
Desktop CO2 reader for sealed rooms and offices that share air with plants.
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Amazon
TIM10 Desktop CO2 Monitor — Data Logging
Logging CO2 monitor that shows the day/night breathing curve of a sealed room.
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Amazon
Autopilot Desktop CO2 Monitor APCEM2
Greenhouse-brand CO2 monitor with a relay-ready design heritage.
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Amazon
Luster Leaf Digital Soil pH Meter Rapitest
Digital soil pH probe from the Rapitest family — in-ground reads without mixing slurry.
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Amazon
Dr.Meter S20 Soil Moisture Meter — Battery Powered
Powered soil probe with a backlit readout — clearer than the free swinging-needle meters.
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Amazon
XLUX T10 Soil Moisture Meter — Long Probe Twin Pack
Two long-probe analog meters — one for the tent, one for the yard.
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Amazon
Hydrometer and Test Jar Kit — for Nutrient and Brewing Checks
Floating hydrometer + jar for specific gravity — handy for teas, ferments and checks.
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Amazon
Sugar Brix Refractometer 0-90% — Fruit and Sap
Wide-range refractometer for fruit ripeness and plant sap checks.
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Amazon
Outlet Power Monitor with Backlight — Voltage and Cost
Plug-through monitor that shows watts, volts and running cost per device.
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Amazon
Infrared Thermometer Mini — Pocket Size
Pocket IR gun for leaf and surface temps on scouting rounds.
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Amazon
Waterproof Digital Thermometer 2-Pack — Aquarium and Reservoir
Stick-on/probe thermometers for reservoirs and tanks — a matched pair.
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