Bluelab OnePen – 3-in-1 Digital pH, EC and Temperature Meter with Bluetooth
The Bluelab OnePen is an advanced digital testing instrument designed to measure pH, electrical conductivity (EC), and temperature in hydroponic nutrient solutions. Combining three essential measurements in one compact device, this professional meter helps growers monitor water quality, manage nutrient concentrations, and maintain suitable growing conditions.
Featuring Bluetooth connectivity and integration with the Edenic by Bluelab app, the OnePen allows users to record measurements, review historical data, and organize testing results from a connected device.
Its backlit display shows pH and EC readings simultaneously, while the replaceable double-junction pH probe and titanium conductivity electrodes provide durable measurement technology for regular use.
With its IP68 waterproof and dustproof construction, the Bluelab OnePen is suitable for indoor growing facilities, hydroponic reservoirs, greenhouse irrigation systems, and professional horticultural applications.
Precise pH, EC and Temperature Measurements
The Bluelab OnePen combines three essential testing functions to help growers evaluate nutrient solution conditions.
pH Measurement
The meter measures acidity and alkalinity from 0.0 to 14.0 pH, with a resolution of 0.01 and an accuracy of ±0.05 pH at 25°C.
Monitoring pH helps growers determine whether their nutrient solution is within the recommended range for their plants, supporting appropriate nutrient availability.
Electrical Conductivity (EC)
Electrical conductivity indicates the concentration of dissolved ions in a solution, making it a useful measurement for managing fertilizer strength.
The OnePen measures EC from 0 to 10 mS/cm and supports several conductivity scales, including EC, CF, ppm 500 (TDS), and ppm 700.
Temperature Measurement
The integrated sensor measures solution temperature from 0 to 50°C (32 to 122°F), with a resolution of 0.1°C.
Tracking reservoir temperature helps growers identify changes that may affect root-zone conditions and nutrient solution management.
Bluetooth Connectivity with the Edenic App
The Bluelab OnePen connects to the Edenic by Bluelab app through Bluetooth, providing convenient digital measurement recording and data management.
Compatible features include:
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Bluetooth Connectivity: Connect the OnePen to the Edenic app on a compatible device.
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Measurement Recording: Save pH, EC, and temperature readings digitally.
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Historical Data: Review previous measurements and identify changes over time.
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Organized Records: Categorize and manage readings from different reservoirs or growing areas.
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Data Sharing: Share recorded information when needed.
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Live Measurement Display: View supported readings through the connected application.
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Software Updates: Access compatible device updates through Edenic.
These functions are particularly useful for growers who want more organized nutrient management records without relying entirely on handwritten notes.
Note: Bluetooth communication requires the OnePen to be within an appropriate connection range of a compatible device. It is not a standalone Wi-Fi monitoring system.
Key Features and Benefits
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Three-in-One Digital Meter: Measures pH, electrical conductivity, and temperature with a single instrument.
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High-Resolution pH Measurements: Provides readings with 0.01 pH resolution.
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Simultaneous Display: Shows pH and EC readings together on a backlit screen.
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Bluetooth Connectivity: Integrates with the Edenic app for measurement recording and data management.
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Replaceable Probe: Allows the sensor assembly to be changed without replacing the complete instrument.
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Double-Junction pH Electrode: Designed for reliable measurements during regular nutrient solution testing.
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Titanium EC Electrodes: Offer corrosion-resistant conductivity measurement technology.
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Probe Health Indicator: Helps users monitor sensor condition and maintenance requirements.
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IP68 Protection: Waterproof and dustproof construction for demanding growing environments.
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Two-Point pH Calibration: Supports calibration using pH 7.0 and pH 4.0 solutions.
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Multiple Conductivity Scales: Displays EC, CF, ppm 500, or ppm 700 measurements.
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Portable Design: Convenient for testing reservoirs, irrigation water, and nutrient solution runoff.
How to Use the Bluelab OnePen
The Bluelab OnePen is designed for straightforward nutrient solution testing.
Step 1 – Prepare the Meter
Remove the protective storage cap and inspect the probe to ensure it is clean and properly hydrated.
Before testing, verify that the instrument is calibrated according to Bluelab's recommendations.
Step 2 – Immerse the Probe
Place the sensor tip into the nutrient solution, ensuring that the measurement components are adequately immersed.
Avoid contact with the sides or bottom of the container when possible.
Step 3 – Read the Measurements
Allow the readings to stabilize before recording the pH and EC values.
The backlit display provides simultaneous measurements, while temperature can be viewed using the appropriate measurement mode.
Step 4 – Record Data with Edenic
If desired, connect the OnePen to the Edenic app through Bluetooth to record and organize measurements.
Step 5 – Clean and Store
After testing, rinse the probe with clean water and replace the protective cap containing appropriate KCl storage solution.
Never allow the pH electrode to dry out.
Technical Specifications
| Specification |
Details |
| Brand |
Bluelab |
| Product Name |
OnePen |
| Product Type |
Digital pH, EC, and temperature meter |
| Measurement Parameters |
pH, electrical conductivity, temperature |
| Connectivity |
Bluetooth |
| Compatible Application |
Edenic by Bluelab |
| pH Measurement Range |
0.0–14.0 pH |
| pH Resolution |
0.01 pH |
| pH Accuracy |
±0.05 pH at 25°C |
| EC Measurement Range |
0–10 mS/cm |
| EC Resolution |
0.01 mS/cm |
| EC Accuracy |
±0.1 mS/cm at 25°C |
| CF Measurement Range |
0–100 CF |
| CF Resolution |
0.1 CF |
| CF Accuracy |
±1 CF |
| ppm 500 Range |
0–5000 ppm |
| ppm 500 Resolution |
10 ppm |
| ppm 500 Accuracy |
±50 ppm |
| ppm 700 Range |
0–7000 ppm |
| ppm 700 Resolution |
10 ppm |
| ppm 700 Accuracy |
±70 ppm |
| Temperature Range |
0–50°C (32–122°F) |
| Temperature Resolution |
0.1°C / 0.1°F |
| Temperature Accuracy |
±1°C / ±1°F |
| Operating Temperature |
0–50°C (32–122°F) |
| pH Probe |
Replaceable double-junction electrode |
| EC Electrodes |
Titanium |
| Protection Rating |
IP68 waterproof and dustproof |
| Display |
Backlit digital display |
| Probe Health Indicator |
Yes |
| pH Calibration |
Two-point calibration |
| Power Supply |
2 AAA alkaline batteries |
| Warranty |
2-year limited warranty; 6 months for the replacement probe |
| Applications |
Hydroponics, nutrient solutions, irrigation water, runoff testing |
Accuracy specifications are stated at 25°C (77°F).
What's Included with the Bluelab OnePen?
The manufacturer's standard package includes:
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1 × Bluelab OnePen with replaceable pH, EC, and temperature probe
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1 × Bluelab Sensor Cleaning Brush
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1 × 18 mL Bluelab pH 7.0 Calibration Solution Sachet
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1 × 18 mL Bluelab pH 4.0 Calibration Solution Sachet
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1 × Bluelab KCl Storage Solution Sachet
The instrument operates using two AAA alkaline batteries.
Additional calibration solutions and the Bluelab OnePen Replacement Probe are available separately.
Maintenance, Calibration and Replaceable Probe
Proper maintenance helps preserve the accuracy of the Bluelab OnePen and extend the useful life of its sensor.
Bluelab recommends cleaning the pH bulb and conductivity electrodes regularly, generally at least once per month depending on use.
The pH electrode should also be kept hydrated and calibrated as recommended by the manufacturer. Use fresh pH 7.0 and pH 4.0 solutions for two-point calibration.
For conductivity calibration, Bluelab provides a procedure using an appropriate 2.77 EC calibration solution.
After use, rinse the probe to remove fertilizer residues and keep the pH bulb hydrated with KCl storage solution. Avoid storing the electrode in distilled, deionized, or reverse-osmosis water.
A major advantage of the OnePen is its replaceable sensor assembly. If the probe becomes worn, damaged, or unable to calibrate correctly despite proper maintenance, the Bluelab OnePen Replacement Probe can be installed without purchasing another complete meter.
Why Choose the Bluelab OnePen?
Accurate nutrient solution testing helps growers make better decisions about fertilizer concentration, pH adjustments, and irrigation management.
The Bluelab OnePen simplifies this process by combining three important measurements in a single portable instrument.
Compared with separate pH and conductivity meters, its integrated design reduces the number of devices needed during routine reservoir testing. The simultaneous pH and EC display also makes it easier to assess solution conditions at a glance.
Bluetooth connectivity adds convenient digital recordkeeping, while the replaceable probe helps reduce long-term equipment replacement costs.
For growers looking for a professional hydroponic pH and EC meter in Canada, the Bluelab OnePen offers accurate measurements, straightforward maintenance, and useful data-management features.
Frequently Asked Questions About the Bluelab OnePen
What does the Bluelab OnePen measure?
The Bluelab OnePen measures pH, electrical conductivity (EC), and temperature in nutrient solutions. It also supports CF, ppm 500, and ppm 700 conductivity scales.
Does the Bluelab OnePen connect to a smartphone?
Yes. The OnePen features Bluetooth connectivity and works with the Edenic by Bluelab app for supported measurement recording, organization, and data management.
Does the Bluelab OnePen measure pH and EC simultaneously?
Yes. Its backlit screen displays pH and electrical conductivity readings together, making it convenient to check nutrient solution conditions.
Can the Bluelab OnePen be used in hydroponic systems?
Yes. It is designed for testing nutrient solutions in hydroponic reservoirs, greenhouse irrigation systems, and other compatible liquid growing applications.
Can the Bluelab OnePen probe be replaced?
Yes. The OnePen features a replaceable sensor assembly. The compatible Bluelab OnePen Replacement Probe is sold separately.
How accurate is the Bluelab OnePen?
According to Bluelab, the meter provides pH accuracy of ±0.05, EC accuracy of ±0.1 mS/cm, and temperature accuracy of ±1°C at 25°C.
Does the OnePen require calibration?
Yes. Regular cleaning and calibration help maintain reliable readings. The device supports two-point pH calibration and conductivity calibration using appropriate reference solutions.
Can the Bluelab OnePen measure soil pH directly?
The OnePen is designed primarily for liquid testing, including nutrient solutions and runoff. For direct pH measurements in soil or growing media, the Bluelab Soil pH Pen is the more appropriate instrument.
Is the Bluelab OnePen waterproof?
Yes. The instrument carries an IP68 protection rating, indicating resistance to dust and water under the conditions specified by the manufacturer.
What is the difference between the Bluelab OnePen and a standard pH Pen?
The OnePen measures pH, EC, and temperature, offers Bluetooth connectivity through Edenic, and features a replaceable probe. A standard Bluelab pH Pen primarily measures pH and temperature.
