Bluelab OnePen Replacement Probe (Coming Soon)

Renew Your OnePen Instead of Replacing It, pH + EC + Temp Sensor

pH sensors wear out with use, and when the OnePen's readings start to drift, the fix is the probe, not the whole pen. This replacement probe swaps in quickly and restores accurate pH, conductivity and temperature readings. It is a cost-effective way to keep your OnePen in service.

Home growers and commercial teams alike can keep a spare on hand to minimize downtime when a probe reaches end of life.

Key Features & Benefits

• Three sensors in one — double-junction pH probe, titanium EC electrodes and temperature sensor.
• Quick replacement — swaps onto the OnePen with minimal downtime.
• IP68 rated — dust and waterproof, like the pen itself.
• Calibration sachets included — one each of pH 7.0, pH 4.0 and KCl storage solution, 18 ml.

Who Should Use the OnePen Replacement Probe

Owners of the Bluelab OnePen (PENONE) whose probe is drifting, slow to respond or no longer holding calibration.

About Bluelab OnePen Replacement Probe

Bluelab gives an average OnePen replacement probe life of about 18 months, depending on care, and a 6-month warranty. Bluelab recommends rinsing after each use and following its cleaning, hydration and calibration guidance.

Frequently Asked Questions

How long does a OnePen replacement probe last?

Bluelab gives an average life of approximately 18 months. Like all pH sensors, it is electrochemical and wears over time, and good care extends its life.

How do I know the probe needs replacing?

Signs include slow response, readings that drift soon after calibration, or failed calibrations even after cleaning and hydration. The OnePen's probe health indicator helps you judge sensor condition.

How do I make the probe last longer?

Rinse the probe after each use so salts do not dry on it, keep it hydrated with KCl storage solution and clean and calibrate regularly. Bluelab's support site has step-by-step care guidance.

Does it work with other Bluelab pens?

No. It is made specifically for the Bluelab OnePen (PENONE). Other Bluelab pens and meters use different probes.