Bluelab pH Pen - Temperature Compensated Digital pH Tester

Bluelab pH Pen - Temperature Compensated Digital pH Tester

SKU: 83698
Bluelab pH Pen - Temperature Compensated Digital pH Tester

Bluelab pH Pen – Temperature Compensated Digital pH Tester

The Bluelab pH Pen is a great little hand-held device for measuring the acidity/alkalinity of your nutrient solution. Bluelab products are trusted by growers across the globe for their accuracy and reliability – the handy new pH Pen is no exception! With temperature compensation, it provides highly accurate readings, as well as displaying the temperature of your nutrient solution onscreen.

  • Bluelab - a proven track record for accuracy and reliability
  • Provides a digital readout of the pH of your nutrient solution
  • Temperature compensated for improved accuracy
  • Backlit LCD display
  • Hold reading function
  • Low battery indicator
  • Manufactured from quality materials
  • Easy push-button calibration with a 30-day indicator
  • Water resistant
  • Auto shut off to conserve battery life
  • Temperature displayed in ºC or ºF


1 x Bluelab pH Pen, 1 x sachet of pH Probe Storage Solution

Check out our complete water conditioning toolkits, which come with an EC meter, pH meter, pH up & down, pH buffer, chlorine neutraliser, jug and syringes. Choose between Essentials and Bluelab versions.

How the Bluelab pH Pen Works

The Bluelab pH Pen contains a special probe which measures both the pH and temperature of a liquid. The end of the meter is dipped into the nutrient solution and switched on. After a short time, the display will settle and the pH and temperature of the liquid will be shown on the LCD readout. Once a reading has been taken, the display will lock until another button is pressed, giving you the chance to remove the meter from the solution and to read the display.

The accuracy of any pH reader can be negatively effected if the temperature of the solution is too high or too low. The on-board computer inside the Bluelab pH Pen uses temperature information to ensure the accuracy of the pH reading by automatically compensating for any differences, meaning that you can take readings with complete peace of mind, knowing that they are proper representations of what is going on inside your nutrient solution.

The Bluelab pH Pen is water-resistant but not waterproof, so shouldn't be fully submerged for any length of time. Calibration is a simple push-button operation and the unit has an auto switch-off facility to preserve battery life. The meter is straightforward to use and features the same build quality and attention to detail that have made Bluelab products the industry standard.

How to Use the Bluelab pH Pen

Check out the One Stop Grow Shop Blog to find out how to get pH right in hydroponics. You'll also find information on calibration and the availability of nutrients at different pH ranges.

Before using for the first time, the Bluelab pH Pen should be soaked in KCL (potassium chloride) solution for 24 hours and then calibrated. The meter should also be re-calibrated once a week if being used daily. Calibration fluids (pH Buffer 4 and pH Buffer 7) are available at OSGS for this purpose. To calibrate the meter, remove the protective end-cap and wet the probe with clean water. Shake out the end to remove excess water and dip into calibration fluid. Holding the calibration button will then begin the automatic calibration process. When this is complete, your Bluelab pH Pen is ready for use.

To change the setting between Celsius and Fahrenheit, use the 'units' button located underneath the 'calibration' button. Press and hold it until the units onscreen start to flash, then short press to switch between to the two settings.

Before every use, always rinse the probe with clean water and shake off the excess. Press the power button and dip the probe into the nutrient solution. After a few seconds the meter will beep, indicating that the pH measurement has been taken. The meter can now be removed and the display read. The pH of your nutrient solution can then be corrected with pH Up or pH Down adjustment fluids before re-testing. The meter can be switched off by pressing the on-off button for 3 seconds. Always rinse the probe with water and shake off the excess before replacing the end-cap after use. Warning: pH adjustment fluids are highly caustic and require careful handling and storage.