Bluelab pH Pen - soil measurement

Product detailed description

The Bluelab pH Pen for soil is a pocket pH metre for growers who want to measure pH directly in substrate, coco, or soil – not just in solution. Its sharp tip reaches the root zone to reveal the actual pH the plant experiences there.

Why it pays off

• Robust tip for direct measurement in substrate – where a standard pen for solution is insufficient, here you measure right at the roots.
• Dual-purpose cap / dibber filled with KCl solution protects and hydrates the probe and also serves to pre-pierce the hole.
• Accuracy ±0.1 pH in the range 0.0–14.0 pH, backlit display, and temperature measurement in Celsius and Fahrenheit.
• Fully waterproof body and automatic shut-off after 4 minutes – the pen withstands the humid growing environment and saves battery.
• Powered by AAA batteries (included) with a one-year warranty.

How to measure correctly in substrate

First pre-pierce a hole in the substrate using the tip of the cap/dibber, then insert the probe – do not push the electrode directly into hard substrate to avoid damage. The probe also works in solution with conductivity of at least 0.2 EC. Calibrate the metre with two-point calibration solutions pH 4.0 and pH 7.0 (or pH 10.0 if you usually measure above 7.0) and keep the probe hydrated by topping up the cap with KCl storage solution.

Which version to choose

Choose this version if you mainly measure in soil and substrate. For measuring in nutrient solution, the Bluelab pH Pen is more practical. If you need a replaceable probe and cable for hard-to-reach places in substrate, see the Bluelab Multimedia pH Metre with Leap probe.

Why monitor pH in the root zone? This is where nutrient uptake is decided – in soil the ideal range is roughly 6.0–7.0, in coco rather 5.5–6.5. Verify the exact range according to your crop and used fertilisers.

Specifications

• pH: range 0.0–14.0, resolution 0.1 pH, accuracy ±0.1 pH (at 25 °C)
• Temperature: 0–50 °C, accuracy ±1 °C
• Calibration: two-point (pH 4.0 and 7.0, optionally pH 10.0), 30-day reminder
• Probe: for direct measurement in substrate, dual-purpose cap/dibber filled with KCl solution (non-replaceable)
• Power supply: 1x AAA alkaline battery, automatic shut-off after 4 minutes
• Water resistance: fully waterproof body
• Display: backlit
• Warranty: 1 year
• Package contents: Bluelab pH Pen for soil, single-use sachets of calibration solutions pH 4.0 and pH 7.0

Frequently asked questions

Can I insert the probe directly into the substrate?

First pre-pierce a hole with the tip of the storage cap, which also serves as a dibber, then insert the probe. Pushing the electrode directly into hard substrate may damage it. This method allows gentle pH measurement directly in the root zone.

Does the pen measure pH in nutrient solution?

Yes, the Bluelab pH Pen for soil works in substrate, coco, and in solution with conductivity of at least 0.2 EC. However, it is optimised for direct measurement in solid media. If you mainly measure in solution, the standard Bluelab pH Pen is more practical.

How do I care for the probe?

Never let the glass probe dry out. The storage cap is filled with KCl solution that keeps the probe hydrated; top it up with KCl storage solution as needed. Operating and storage temperature is 0–50 °C. Regular care significantly extends probe life.