Getting started: The Bluelab pH Pen

Product overview and how to get started


The Bluelab pH Pen is a hardy, compact, and accurate pH and temperature pen for using in nutrient solution. Use the pH pen to quickly and accurately know if your solution is too acidic or alkaline, or too hot or cold. Designed for everyday use, the Bluelab pH Pen helps you to keep your plants in the  optimal pH and temperature range so that your plants can thrive. 

Getting started is easy. Follow the instructions to hydrate and calibrate your pen, and submerge the probe in your nutrient reservoir to view the measurement on the display.   


Backlit LCD display  

Low battery indicator  

Hold reading function  

Fully waterproof 

Fully guaranteed for 1 year (with proof of purchase) 

Auto-off function 

Double junction probe  

Automatic Temperature Compensation (ATC) 

Successful calibration indicator  

Selectable units for °C and °F  

Register your product with Bluelab

Product manuals:

PENPH User Manual - English

PENPH User Manual - Spanish

PENPH User Manual - German Deutsch

PENPH User Manual - Dutch

PENPH User Manual - Latin American Spanish

PENPH User Manual - Canadian French

PENPH User Manual - French

Get started 

Get started with the Bluelab pH Pen in 3 easy steps: 

  1. Hydrate your Bluelab pH Pen. Before first use, you must first hydrate the pH pen in KCl solution for 24 hours and then calibrate the pen using the calibration guide below. 
  2. Calibrate your pH pen. Calibrate before first use and return to this guide if you need a monthly calibration refresher.
  3. Take your first measurement. Submerge the probe in your nutrient reservoir to view the readings on the display.  Read this guide for correct usage.


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