Testers & Meters

Used and/or refurbished Testers & Meters for your growing needs. Having the correct testers and meters is vital for your grow. Our inventory is constantly moving, so make sure to visit us often if you don't find the model that you need.
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Bluelab pH Pen (used)

The Bluelab pH Pen will quickly and accurately measure your hydroponic solution’s acid/alkaline balance. Use to maximize plant nutrition and ensure optimum plant health, growth and yields.

• Successful calibration indicator
• Measures pH and temperature
• Completely waterproof
• Backlit LCD display
• AAA alkaline battery included

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Champ (HI98106) (used)

The Champ is a HANNA pH Tester that fits comfortably in your hand and includes a larger LCD which makes it easier to read at any angle.

With the latest innovation of a renewable cloth junction the new HANNA meters last much longer. Simply pull out 1-2 mm (1/8-inch) of the junction fiber to completely renew the junction. Calibration is performed manually at 1 point with a trimmer located on the side of the tester.

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pHep 4 (HI98127) (used)

Each pHep4 HANNA pH Meter has a dual-level, digital LCD that displays both pH and temperature (C° or F°). At start-up, the instrument performs a self check then displays the remaining battery level to assure proper working condition.

The handheld HI 98127 includes a sensor/ electrode, probe removal tool, batteries and complete instructions. Warranty: 1-year (six months on electrode).

• Dual level display showing pH and temperature
• Automatic temperature compensation
 Replaceable pH electrode featuring an extendable junction
• Rugged waterproof casing
• Automatic calibration

Size: 6.4″ tall x 1.6″ wide x 1.0″ deep

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Bluelab PH Probe with 2000 mm cable
Sensor probes do not last forever and will eventually fail. This pH Electrode is gel filled making it maintenance free. It’s designed for use with all Bluelab pens, meters and monitors. 

• Fully waterproof, submersible to 10 meters 
• Quality BNC connection 
• Tough polypropylene barrel
• Heavy duty thick wall glass stem 

No warranty on items sold.  Each probe has been tested before shipping.
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Oakton Ecotestr PH 1 (used)
Economical, pocket-sized meter. Waterproof, dust proof housing that floats. Easy to use; push-button calibration with auto buffer recognition. Includes transparent electrode cover / sample cup. Push-button calibration, HOLD function, and error messages

Range: 0.0 to 14.0 pH 

One point calibration
Power: four 1.5 V button cell batteries (not included) 
50 per master case
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Oakton EcoTestr TDS Low (used)

Economical conductivity and TDS pocket meters featuring a large, ergonomically designed display so that you can easily view measurements at a glance. The orientation of the display means there’s no need to turn your head or tilt the tester. Waterproof and dust proof housing is designed for use in dirty and damp field conditions. Convenient, built-in belt/pocket clip keeps the tester accessible when not in use.

Stainless steel electrodes are both rugged and chemical resistant, for use in a wide variety of applications. Single-point electronic calibration means you are ready to measure quickly and easily. Additional features include auto-shutoff to prolong battery life, hold function to lock in a measured value, and self-diagnostic error messages. Testers also have a self-adjusting TDS factor from 0.40 to 1.0.

Battery included.

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Bluelab Guardian Monitor (used)
In just one glance the Bluelab Guardian Monitor measures all three critical parameters for healthy plant growth; pH, conductivity and temperature. 

• 'Plant Safe' green LED display 
• Selectable values for conductivity and temperature 
• Simple push button pH calibration 
• No calibration required for conductivity and temperature 
• Silent alarm for both high and low settings 
• Automatic temperature compensation 

Easy to use, just plug it in and place the probes in your nutrient reservoir. 

Battery and probes included.
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Bluelab PPM Pen (used)

The Bluelab Conductivity Pen is an easy-to-use handheld meter that quickly and accurately measures if your crop is receiving the right amount of nutrients. Use to maximize plant health, prevent nutrient burn and ensure optimum plant yields.

• Selectable units for conductivity (EC or PPM) and temperature
• Successful calibration indicator
• Backlit LCD display
• Fully waterproof
• AAA alkaline battery included

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Hydrofarm - Active Eye Digital Light Meter (useds)

This product is a precision instrument used to measure luminance (footcandles). The meter is fully cosine corrected for the angular incidence of light, meaning that if you are not holding the sensor perfectly perpendicular to the light source, the sensor will still read the light correctly.

The sensor is stable and made of a long-life silicon photo diode. The digital light meter accurately measures to 40,000 FC. The meter’s built-in low battery indicator means you’ll never be caught by surprise by a low-power product.


  • Measures grow lights or sunlight
  • Measures up to 40,000 footcandles
  • 3 scales for precise readings
  • Convenient hand-held remote sensor
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