Bluelab OnePen Replacement Probe – Replacement Probe for Bluelab OnePen

Bluelab OnePen Replacement Probe is an original replacement probe designed for the professional Bluelab OnePen meter. It measures pH, electrical conductivity (EC) and temperature, restoring the meter's full accuracy without the need to buy a new meter. Thanks to the easy replacement system, changing the probe takes only seconds and significantly extends the service life of the Bluelab OnePen.

Bluelab OnePen Replacement Probe was developed as a replaceable measurement module for the Bluelab OnePen and is one of the greatest advantages of this professional meter. Instead of replacing the entire device when the electrode wears out, you only need to replace the probe, reducing costs and minimising waste.

The probe combines a high-quality double-junction pH electrode, titanium EC electrodes and a temperature sensor, providing exceptionally accurate and fast measurements of all key nutrient-solution parameters. Thanks to the materials used, it is resistant to aggressive environments and intensive daily use.

The housing is IP68 certified, providing excellent protection against water and dust. After installation, the probe is calibrated in the standard way using pH 7.0 and pH 4.0 buffer solutions and is ready for use.

Technical specifications

✔️ Manufacturer: Bluelab

✔️ Model: OnePen Replacement Probe

✔️ Type: Replacement probe

✔️ Compatibility: Only with Bluelab OnePen

✔️ Measured parameters:

• pH
• EC (Electrical Conductivity)
• Temperature

✔️ pH range: 0.0 – 14.0 pH

✔️ EC range: 0.0 – 10.0 EC

✔️ CF range: 0 – 100 CF

✔️ TDS (500 Scale): 0 – 5000 ppm

✔️ TDS (700 Scale): 0 – 7000 ppm

✔️ Temperature range:

0 – 50°C

32 – 122°F

✔️ Double Junction pH technology

✔️ Titanium EC electrodes

✔️ Automatic temperature compensation

✔️ Water- and dust-resistant IP68 construction

✔️ Quick and easy tool-free replacement

📦 The set includes

✔️ 1 × Bluelab OnePen Replacement Probe

✔️ 1 × Buffer solution pH 7.0 (18 ml)

✔️ 1 × Buffer solution pH 4.0 (18 ml)

✔️ 1 × KCl Storage Solution – storage solution (18 ml)

Benefits

✔️ Replace only the probe, not the entire device

✔️ Significantly extends the life of the Bluelab OnePen

✔️ Simultaneously measures pH, EC and temperature

✔️ Double-junction pH electrode for longer life

✔️ High-resistance titanium EC electrodes

✔️ High accuracy and rapid reading stabilisation

✔️ Easy replacement in seconds

✔️ IP68 protection against water and dust

✔️ Reduces maintenance costs

✔️ Genuine Bluelab replacement component

🔧 Application

Suitable for:

• Bluelab OnePen

• Hydroponic systems

• Coco coir substrate

• Soil cultivation

• Aquaponics

• Measuring nutrient solutions

• Greenhouses

• Professional horticulture

• Laboratory applications

📋 How to use

1. Unscrew the old probe from the Bluelab OnePen.
2. Install the new replacement probe.
3. Calibrate the probe with pH 7.0 and pH 4.0 buffer solutions.
4. Rinse the probe with clean water after every use.
5. Always store the electrode in the included KCl Storage Solution when the instrument is not in use.

⚠️ Important: The average service life of the probe is approximately 18 months, depending on use and maintenance. Regular cleaning, proper storage and periodic calibration can significantly extend its lifespan. The probe comes with a 6-month limited warranty.

💡 Urban Botaniks tip: If you notice slower stabilisation of readings or difficulties calibrating the Bluelab OnePen, the most common cause is a worn probe. Replacing it restores the factory measurement accuracy and is a significantly more economical solution than buying a new instrument.