Bluelab Soil pH Pen. Direct Root Zone pH & Temperature Measurement Tool

The Bluelab Soil pH Pen is a precision handheld instrument designed for direct measurement of pH and temperature in soil, coco coir, rockwool, and nutrient solutions. Engineered to eliminate traditional slurry testing methods, it provides fast, accurate readings directly at the root zone, improving nutrient management and plant health.

Featuring a double-junction pH probe, the device delivers stable and reliable measurements while reducing contamination and extending probe lifespan. The integrated temperature sensor allows simultaneous monitoring, ensuring optimal growing conditions across varying environments.

A dual-purpose storage cap and dibber enables easy insertion into media, allowing consistent and repeatable root zone measurements without disturbing plant structure. The probe is kept hydrated using a KCl-filled storage system, maintaining accuracy over time.

With a waterproof construction and backlit display, the Soil pH Pen is designed for practical use in both indoor grow rooms and outdoor environments.

Key Benefits

Direct root zone pH measurement without slurry testing. Eliminates the inaccuracy and time cost of traditional slurry or pour-through methods by measuring pH directly in the growing media.
Simultaneous pH and temperature measurement. Integrated temperature sensor captures both parameters in a single insertion for complete root zone condition monitoring.
Double-junction pH probe for accuracy and longevity. Reduces reference contamination and extends probe working life compared to standard single junction electrodes.
Suitable for soil, coco, rockwool, and nutrient solutions. Versatile measurement capability across the most common hydroponic and soil-based growing media.
Dual-purpose storage cap and dibber. The storage cap doubles as a dibber for easy, consistent probe insertion into growing media without disturbing root structure.
Fully waterproof construction. Durable housing rated for use in wet grow environments with a backlit display for clear readings in all lighting conditions.

How It Works

Insert the probe directly into soil or growing media. Use the dibber cap to create a clean insertion point, then push the probe to the root zone for direct measurement.
Sensor measures pH and temperature simultaneously. The double-junction electrode and integrated temperature sensor capture both parameters instantly at the point of insertion.
Readings displayed instantly on the backlit screen. pH and temperature values appear immediately for fast, on-site assessment without app dependency.
KCl storage cap maintains probe hydration between uses. The filled storage cap keeps the double-junction electrode hydrated during storage, preserving sensor accuracy over time.
2-point calibration with 30-day reminder. Simple calibration process with a built-in reminder function ensures the probe maintains accuracy across regular use cycles.

System Features

Dual-purpose storage cap and dibber. Serves as both a probe insertion tool and a KCl-filled storage cap for convenient, all-in-one field use.
Double-junction pH electrode. Reduces contamination of the reference solution and extends probe lifespan beyond standard single junction designs.
Integrated temperature sensor. Simultaneous temperature measurement eliminates the need for a separate thermometer in the grow environment.
Backlit LCD display. Clear, readable output in all lighting conditions including low-light grow rooms and outdoor environments.
2-point calibration with reminder. Calibration reminder function prompts growers at 30-day intervals to maintain measurement accuracy.
Fully waterproof housing. Durable construction for reliable performance in wet and humid grow environments.
Compact ergonomic handheld design. Lightweight and portable for easy use across multiple plants, containers, and grow sites.

Measurement Capabilities

pH Measurement. Accurate direct root zone pH readings in soil, coco coir, rockwool, and nutrient solutions.
Temperature Measurement. Integrated sensor captures root zone environmental temperature for complete growing media condition monitoring.

Applications

Bluelab Soil pH Pen for direct root zone pH testing in soil and coco Australia
Digital soil pH meter for hydroponic substrate and growing media testing
Coco coir pH tester for recirculating and run-to-waste hydroponic systems
Root zone pH sensor for precision nutrient management in indoor growing
Soil and substrate pH measurement device for commercial and hobby growers
Waterproof pH and temperature pen for grow rooms and outdoor growing environments

Ideal For

Soil and coco growers. Direct substrate measurement eliminates slurry testing and provides accurate root zone pH data for precise nutrient management.
Root zone nutrient management. Real-time pH data at the root zone enables growers to identify and correct nutrient lockout conditions before they affect plant health.
Hydroponic and mixed media systems. Compatible with soil, coco coir, rockwool, and nutrient solutions for versatile use across multiple growing methods.
Precision agriculture and indoor growing. Accurate, repeatable measurements support data-driven growing decisions for improved consistency and yield.

What Sets It Apart

The Bluelab Soil pH Pen is engineered for direct root zone analysis, eliminating inaccurate slurry testing and providing real-time pH and temperature insights at the point of measurement. Its double-junction probe, KCl storage system, and dual-purpose dibber cap make it a practical, accurate, and durable tool for precision nutrient management across soil, coco, and hydroponic growing systems.

Technical Specifications

Measurement Parameters. pH and temperature (simultaneous)
pH Probe. Double-junction electrode
Calibration. 2-point calibration with 30-day reminder
Display. Backlit LCD
Waterproof Rating. Fully waterproof
Storage System. KCl-filled dual-purpose cap and dibber
Compatible Media. Soil, coco coir, rockwool, and nutrient solutions
Product Weight. Approximately 0.3 to 0.4 kg
Packaged Shipping Weight. Approximately 0.5 to 0.7 kg

Frequently Asked Questions

How often should I calibrate Bluelab Soil pH Pen?

pH meters should be calibrated before every use or at minimum every 2–3 days during active grows. EC meters are more stable but should be verified against a known reference solution weekly. Bluelab Soil pH Pen uses two-point calibration for pH (4.0 and 7.0 buffer solutions) and single-point calibration for EC (2.77 mS/cm standard). Regular calibration is the single most important factor in measurement accuracy.

How do I store Bluelab Soil pH Pen properly?

Always store pH probes wet — never allow the probe tip to dry out as this permanently damages the glass membrane. Use the probe storage solution supplied with Bluelab Soil pH Pen or Bluelab KCl storage solution. EC probes are more robust but should also be rinsed with clean water after each use. Store Bluelab Soil pH Pen at room temperature away from direct sunlight.

What should I do if Bluelab Soil pH Pen is reading incorrectly?

First, recalibrate using fresh buffer solutions — old or contaminated calibration fluid is the most common cause of inaccurate readings. Rinse the probe thoroughly with deionised or distilled water between calibrations. If readings are still inconsistent after recalibration, check the probe for physical damage or contamination. Most probes have a service life of 12–18 months with proper care.

Is Bluelab Soil pH Pen waterproof?

Check the IP rating listed in the product specifications. Most handheld meters are splash-proof but not designed for submersion. Take care when measuring in deep reservoirs to avoid dropping the unit. Bluelab Soil pH Pen is designed for hydroponic nutrient solution testing — it is not rated for outdoor or continuous immersion use.

Does Bluelab Soil pH Pen ship fast within Australia?

Yes — Bluelab Soil pH Pen ships from our Australian warehouse with fast tracked delivery Australia-wide. Most east coast orders arrive within 2–5 business days. WA, NT, and TAS orders typically arrive within 5–12 business days.