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The Bluelab pH Pen is a waterproof digital meter providing accurate, instantaneous pH and temperature readings (0.0–14.0 pH) for hydroponics. Featuring a 30-day calibration reminder and a double-junction probe, it's essential for monitoring nutrient solution health.
- The Bluelab pH Pen is the ultimate handheld tool for monitoring and mastering the vital pH and temperature of your hydroponic nutrient solution. This compact, professional-grade digital pH meter is trusted by growers worldwide for its reliable, fast, and highly accurate measurements (0.0 to 14.0 pH). Since pH levels are crucial for hydroponic success, this pen is essential for maximising the nutrient uptake of your plants, ensuring robust health and optimal yields. Its rugged, waterproof design and smart features make it the best choice for daily, hassle-free water quality testing. Pair with the Bluelab Conductivity Pen for a complete measurement system.
Key Benefits of the Bluelab pH Pen
- Dual Measurement: Provides fast, accurate readings of both pH and temperature (°C or °F), which is essential for diagnosing root zone issues and optimising nutrient availability.
- Reliable Sensor Technology: Features a resilient double-junction pH probe for extended lifespan and stability in challenging nutrient solutions.
- Smart Calibration Reminder: Includes a 30-day calibration indicator (check mark disappears) to alert you when the simple 2-point calibration is due, maintaining high precision.
- Waterproof Durability: The pen is fully waterproof and designed to float, protecting the unit from accidental drops into the reservoir.
- Temperature Compensated: Offers Automatic Temperature Compensation (ATC), ensuring the pH reading is accurate regardless of the solution temperature.
How to Use the Bluelab pH Pen
Achieving precise and consistent readings with your Bluelab pH Pen requires correct usage and maintenance:- Hydration (Initial Setup): If the probe tip appears dry, you must first hydrate the pen for at least 24 hours in a KCI Storage Solution (never use pure water like RO or distilled water).
- Calibration: Calibrate the pen monthly, or whenever the calibration tick mark disappears. Perform a 2-point calibration using fresh pH 7.0 and either pH 4.0 or pH 10.0 buffer solutions to ensure maximum accuracy across the required range.
- Measurement: Turn the pen on, remove the storage cap, and immerse the probe tip into the nutrient solution (at least 2cm/1"). Wait for the reading to stabilise on the backlit display. Use the 'Hold' button to lock the reading if required.
- Cleaning & Storage: Always rinse the probe under clean tap water immediately after use. Gently replace the cap, ensuring it contains 3-5 drops of KCI storage solution to keep the probe tip continuously moist.
pH Management Guide: Understand the importance of precise control by reading Why pH Levels Are Crucial for Hydroponic Success.Grow Room Guide: For setup and maintenance advice, explore 5 Essential Tips for Setting Up a Hydroponics Grow Room.Frequently Asked Questions
My pH pen reading is stuck on 7 pH, what should I do?
A reading persistently stuck near pH 7.0 often indicates that the delicate glass bulb of the probe is damaged or broken. Since the probe on the Bluelab pH Pen is not replaceable, if thorough cleaning and rehydration fail to correct the issue, the pen will likely need to be replaced.Why can't I store my pH probe in RO or Distilled Water?
Pure water, such as RO or distilled water, actively draws out the reference electrolyte solution from the double-junction probe, essentially draining its chemical potential and causing permanent damage. To avoid this, always store the probe tip wet using a storage solution.What happens if the probe tip accidentally dries out?
If the probe tip dries out, its function may be compromised. To correct this, you must rehydrate the pen for a full 24 hours in a pH probe storage solution, available from pH Management. After rehydration, clean and recalibrate the pen immediately to check if the sensor has suffered permanent damage.How often should I calibrate the Bluelab pH Pen?
Bluelab recommends calibration at least once a month. The pen features a handy check mark indicator that disappears 30 days after the last successful calibration, serving as a visual reminder that it is time to perform the 2-point calibration procedure again.SKU: 1108 - Measures pH and temperature
- Selectable units for °C & °F
- Backlit LCD display
- Double junction probe (not replaceable)
- Successful pH calibration indicator
- Hold function
- Low battery warning
- Fully waterproof
- Auto off function
- Automatic temperature compensation
- 1 year warranty
Free delivery on orders over £60*
- UK Mainland onlyStandard Delivery £4.95
- Heavy / Large item surcharge £2 per item
- 1-3 Days**
- UK Mainland onlyExpress Delivery £8.95*
- Next Working Day**
- UK Mainland onlyScottish Highlands £15.95*
- 2-5 Days***Can not be used with Heavy / Large items
**If ordered on a working day before 2pm cut off (Saturday and Sunday are not classed as working days).Please See Delivery and Returns page for more details.