bluelab pH Pen Installation guide

FAQ and troubleshooting for the Bluelab pH
Pen
Find answers and solutions to common questions for the Soil
pH Pen, pH Pen, and Bluelab pH probes
In this guide:
•General questions
•Understanding error messages
•Troubleshooting
General questions
My pH product won’t calibrate, what should I do?
The first step is to make sure the glass tip of the probe is both well hydrated and clean.
•Learn how to hydrate your pH pen in our guide
•Learn how to calibrate your pen in our guide
If, after both hydrating and cleaning, your pH pen still won’t calibrate, it may be at the end of its
life. Please reach out to our support team if you have further questions.
My pH reading is stuck on 7 pH, what should I do?
Inspect the glassware for damage. If the pen reading is stuck on 7 pH (or close to that), it is likely
the glassware is damaged. The pH pen likely needs replacing.
My pH probe has accidentally dried out, what should I do?
The probe must be rehydrated for 24 hours in KCI storage solution (never use RO, distilled
or deionised water). Next, carry out a calibration to check the probe hasn’t suffered permanent
damage.
There is a salt crust on my probe –why?
Both the pH pen/probe and the storage cap contain KCl (Potassium Chloride) solution. The result
of a small level of evaporation of KCl is the formation of a salt crust as KCl is a type of salt.

This salt crust is normal and will not harm the probe or meter. Gently wash the salt off under
fresh running water. It is essential to ensure that your probe has sufficient KCl in the storage cap
at all times to remain hydrated.
How long will my Bluelab pH Pen last?
Bluelab's pH products are charged with reference material which expends over time and use. The
average life span of a pH pen is approximately 18 months. Good care will help to maintain your
pen. Follow our guides to proper hydration, regular cleaning and calibration.
The pH pen has a 1-year warranty so if you encounter any issues with your current unit, please
feel free to reach out to us for support.
What is KCl Storage Solution?
Our Bluelab pH Probe KCl (Potassium Chloride) Storage Solution is a storage solution designed
specifically for use with Bluelab pH Pens or pH Probes.
Storage solution is used to ensure a pH probe is kept in ideal conditions during storage, while the
probe is not in use. Read more about KCl solution.
Understanding error messages
Error code
Reason
Correction
Calibration solutions may be
contaminated
Always use fresh calibration
solutions

Temperature under range
Temperature over range
Probe not hydrated or clean
Follow the cleaning and
calibration steps
Probe damaged
Replace the pH pen
pH under range
pH over range
Wrong calibration sequence
Calibrate to pH 7 first, then to
pH 4
Probe damaged
Replace the pH pen

pH calibration failed
Calibration solutions may be
contaminated
Always use fresh calibration
solutions
Probe not hydrated or clean
Follow the cleaning and
calibration steps
Probe damaged.
Replace the pH pen
Hardware error
The pH probe may be
damaged
Check for broken glass on the
tip of the pen’s pH probe.
Consider replacing your pH
pen.
Troubleshooting
Trouble
Reason
Correction

Drift –readings slowly
varying
Glassware not clean
Clean glassware, hydrate, then
calibrate
Wick contaminated or blocked
Soak probe in KCl storage
solution for 24 hours and
retest. Don't measure proteins
or oils with the pH pen. You
may need to replace the pH
pen.
Glassware aged
Replace the pH pen
Unsuccessful calibration
Glassware not clean
Clean glassware
Glassware aged (glassware
won't clean)
Replace the pH pen
Probe not hydrated
Soak the probe in KCl solution
for 24 hours and retest
Noisy –readings jumping
around
Contact zone not immersed
correctly
Lower pen into solution at
least 2cm/1"
Reading stuck on 7 pH
Broken glassware
Replace the pH pen
Incorrect sample reading
following successful
calibration
Wick blocked
Soak probe in KCl storage
solution for 24 hours and
retest. Don't measure proteins
or oils with the pH pen.
Still can’t find what you're looking for? Contact Support
How to take a measurement with the Bluelab
pH Pen
Before you use the Bluelab pH Pen, you need to hydrate the probe tip in KCl storage solution for
24 hours, then calibrate the pen to 2 pH points.
•How to hydrate your pH pen
•How to calibrate your pH pen
1. Turn the pH pen on

Press the power button. To turn pen off, press and hold the power button until “OFF” is
displayed.
Note: The pen will automatically turn off after 4 minutes to conserve battery power.
2. Measure pH
Remove the storage cap, place probe in solution and wait for the reading to stabilise.
3. To hold the reading
To hold the reading on the display, short press the power button. To turn hold mode off, press the
power button again.

4: Measure temperature
If you prefer to take your readings in °C or °F you can change the temperature units. Hold down
the Units button for 3 seconds until the temperature units start flashing. Short press the units
button again to cycle between °C and °F. To exit this mode don’t press anything for 3 seconds.
Note: You can change units while in hold mode by holding down the Units button.
5: Rinse and replace storage cap solution
To ensure accurate pH readings, always rinse the probe in fresh water before replacing the cap.
Add 3-5 drops of Bluelab KCl Storage Solution into the wetting seal of the cap each week. Make
sure the cap is on correctly; it will click when in place.
Important: Keep your probe tip wet at all times to avoid permanent damage.
If your readings aren't what you expect, or the pH pen won't take a reading, follow our
troubleshooting and FAQ guide.

Getting started: The Bluelab pH Pen
Product overview and how to get started
Overview
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.
Features

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 1-year limited written warranty with Bluelab
•Download a PDF of the technical specs in English
•Download a PDF of the Bluelab pH Pen manual in your language:
oEnglish
oGerman
oSpanish
oLatin American Spanish
oDutch
oCanadian 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.
Still can’t find what you're looking for? Contact Support