Bluelab OnePen | pH EC Temperature Meter

Bluelab OnePen | pH EC Temperature Meter

Accurate control of nutrient solution pH, conductivity and temperature is critical in hydroponics, protected cropping and intensive irrigation systems. The Bluelab OnePen is an advanced 3-in-1 handheld meter that measures pH, conductivity (EC) and temperature in nutrient solutions, helping growers optimise nutrient uptake, reduce waste and maintain consistent crop performance.

Key Features and Specifications

• 3-in-1 portable meter measuring pH, conductivity (EC) and temperature in nutrient solutions.
• Simultaneous on-screen display of pH and EC for faster decision-making.
• Replaceable combination probe measuring pH, EC and temperature to extend instrument life.
• Double-junction pH sensor and titanium EC electrodes for durability and stable readings.
• Bright, high-contrast backlit LCD with ergonomic, compact pen-style design.
• Bluetooth connectivity to the Edenic app for real-time data logging, storage and sharing.
• Probe health and calibration status indicators, with simple two-point pH calibration (pH 7 and pH 4 or 10).
• Automatic temperature compensation for both pH and EC.
• IP68-rated dustproof and waterproof housing for use in harsh grow environments.
• Powered by 2 x AAA alkaline batteries with auto-off and backlight time-out to conserve power.
• Compatible with Bluelab OnePen Replacement Probe and Bluelab pH Probe KCl Storage Solution (available separately).

Technical Specifications

Application and Usage Instructions

The Bluelab OnePen is suitable for hydroponics, fertigation systems, greenhouse crops and any application requiring accurate measurement of solution pH, EC and temperature.

• Use to measure nutrient solution, stock tanks, irrigation run-off or water source quality.
• Select measurement mode (pH/Temp, EC/Temp, EC/pH or mV/Temp) using the CAL button.
• Immerse the probe so both the pH glass bulb and titanium EC electrodes are fully covered (at least 3 cm).
• Allow readings to stabilise, then press the power/measure button to hold and save the measurement; values can be synced to the Edenic app if connected.
• Perform two-point pH calibration regularly using fresh pH 7.0 and pH 4.0 or 10.0 buffer solutions, following the on-screen prompts.
• EC calibration is factory-set; a 2.77 EC check solution can be used and EC calibration performed if required (firmware v1.0.6+ via Edenic).
• Rinse the probe in fresh tap water between solutions to avoid cross-contamination.
• Maintain the probe by keeping the pH bulb hydrated in Bluelab KCl Storage Solution when not in use, cleaning with Bluelab Probe Cleaner and brush, and avoiding RO, distilled or deionised water on the bulb.
• Replace the combination probe when it no longer calibrates or readings become unstable; the replacement probe attaches using the threaded collar and alignment notch.

What is Included

• Bluelab OnePen handheld meter with replaceable pH/EC/temperature probe.
• 2 x 18 ml Bluelab pH calibration solution sachets.
• 1 x 18 ml Bluelab KCl storage solution sachet.
• Bluelab sensor cleaning brush.
• User manual.

Professional 3-in-1 solution meter for controlled environments

The Bluelab OnePen combines precise pH, EC and temperature measurement with Bluetooth data logging and robust IP68 construction, making it a practical tool for commercial greenhouses, hydroponic growers and research facilities. Used with the Edenic app and a regular calibration and maintenance program, it supports consistent nutrient management and reliable crop performance.