Bluelab® OnePen — pH, Conductivity (EC) & Temperature with Replaceable Probe

Three Critical Measurements. One Pen. One Click. — Bluelab® OnePen

The Bluelab® OnePen eliminates the need to carry and manage separate pH, EC, and temperature meters for nutrient solution monitoring. With a single replaceable probe measuring all three parameters — pH, electrical conductivity (EC), and temperature — and one-click data capture, the OnePen streamlines the measurement workflow for commercial hydroponic growers, allowing faster, more frequent testing across large growing environments without the complexity of managing multiple devices.

Bluelab is the globally trusted standard for hydroponic measurement equipment — known for accuracy, reliability, and purpose-built design for the unique demands of nutrient solution management. The OnePen's replaceable probe design extends the meter's service life beyond that of fixed-probe alternatives, reducing long-term measurement tool costs for commercial operations where probe wear from frequent testing is a consistent challenge.

Key Features & Benefits

• Three-in-One Measurement: Measures pH, EC, and temperature with a single probe insertion — eliminates the need to switch between separate meters for complete nutrient solution analysis.
• Replaceable Probe: Worn or damaged probes can be replaced without discarding the entire meter — extending the OnePen's service life and reducing long-term equipment costs in high-frequency testing environments.
• One-Click Data Capture: Instant reading capture and logging with a single button press — reduces testing time and operator error during nutrient solution monitoring across large growing facilities.
• Bluelab Accuracy: Manufactured to Bluelab's precision measurement standards — trusted by commercial hydroponic growers worldwide for accurate, consistent pH and EC readings critical to nutrient solution management.
• Compact Pen Form Factor: Slim, portable pen design fits in a shirt pocket or tool belt — easy to carry during grow room rounds and nutrient reservoir checks across large facilities.
• Temperature Compensation: Integrated temperature measurement enables automatic temperature compensation for EC readings, ensuring accurate nutrient concentration data regardless of solution temperature variation.

Who Should Use the Bluelab OnePen

Commercial hydroponic growers, nutrient solution managers, and grow room technicians who need fast, accurate pH and EC monitoring across multiple reservoir or fertigation points. Ideal for any operation where frequent nutrient solution testing is a daily workflow requirement and single-meter simplicity improves consistency and speed.

Calibration & Maintenance

Calibrate the pH probe regularly using Bluelab calibration solution — pH calibration frequency depends on usage intensity and the pH range of solutions being measured. Rinse the probe with clean water and store in Bluelab probe storage solution (or pH 4.0 calibration solution) when not in use to maintain probe life and reading accuracy. Replace the probe when pH readings drift significantly between calibrations.

Frequently Asked Questions

How often does the OnePen probe need replacing?

Probe replacement frequency depends on usage intensity, solution types, and storage practices. With proper maintenance (regular calibration and correct storage), Bluelab probes typically last 12-24 months under commercial-use conditions.

What calibration solutions are needed?

pH calibration requires Bluelab pH 4.0 and pH 7.0 (or pH 7.0 and pH 10.0 depending on your pH range) calibration solutions. EC calibration uses Bluelab 2.77 EC calibration solution. Use Bluelab-branded solutions for best calibration accuracy.

Does the OnePen have data logging capability?

The OnePen features one-click data capture. For full data logging, exporting, and trend analysis, pair with Bluelab's compatible data management tools or accessories — refer to Bluelab's documentation for compatible data capture options.

Is the OnePen waterproof?

Refer to Bluelab's product specifications for the OnePen's IP waterproofing rating. Exercise appropriate care when using in environments with splashing or immersion risk, as per the product's rated protection level.