Description
Read pH straight from the root zone, no slurry needed
The Bluelab Soil pH Pen measures pH and temperature directly in soil, coco coir, rockwool and potting mixes, and in nutrient solution too. Rather than mixing a soil slurry and waiting, you push the built-in storage cap/dibber into the medium to open a pathway, then slide the probe into the hole for a reading at the roots. A double-junction pH probe, automatic temperature compensation and a backlit display make it an everyday tool for containers, raised beds, polytunnels and grow tents alike.
Key Benefits
- Direct root-zone readings in soil, coco, rockwool, potting mix and solution
- Integrated storage cap/dibber makes a safe hole for the probe and keeps the tip wet in KCl solution
- ±0.1 pH accuracy with 0.1 pH resolution and automatic temperature compensation
- Two-point calibration with a 30-day reminder – the tick disappears when it is due
- Fully waterproof, with hold function, auto-off and low-battery warning
- About 350 hours of use from one AAA battery
Nutrient Lockout Hiding in the Root Zone
In soil and soilless media, pH decides which nutrients plants can actually take up. Too acidic and phosphorus becomes scarce while aluminium and manganese can build to toxic levels; too alkaline and phosphorus, zinc and boron are locked away. Either way you get poor nutrient uptake, pale or stunted growth and deficiency symptoms even when the feed is right. Bluelab recommend pH 6.2–7.2 for soil crops and 5.5–6.3 in solution, though the ideal is plant specific. Testing the medium itself, rather than runoff alone, shows you what the roots are really sitting in.
How to Use
- Before first use: check the tip is covered by KCl solution in the cap, then calibrate in pH 7.0 and pH 4.0 using the sachets supplied.
- Open a pathway: clear the top 5–10 cm of soil, push the cap/dibber in up to the 'soil' mark and lift it out.
- Measure: twist to loosen and remove the cap, switch on and lower the probe into the hole with no sideways force; read once the value settles.
- Dry media: moisten with RO or distilled water and ideally wait 24 hours, as tap water shifts the reading.
- Beds and borders: test several spots and average the readings.
- Rinse the tip in fresh tap water after every reading, clean it at least monthly and recalibrate after each clean.
Technical Specifications
- Measures: pH and temperature
- pH: 0.0–14.0, resolution 0.1, accuracy ±0.1 at 25 °C
- Temperature: 0–50 °C / 32–122 °F, resolution 1, accuracy ±1 °C / ±2 °F
- Media: soil, coco coir, rockwool, potting mixes and nutrient solution (0.2 EC and above)
- Operating environment: 0–50 °C; do not use or store outside this range
- Temperature compensation: automatic (ATC)
- Calibration: two-point, pH 7.0 and 4.0 (or 7.0 and 10.0), 30-day reminder
- Display: backlit LCD with hold function; auto-off after 4 minutes
- Probe: double-junction pH probe with integrated storage cap/dibber
- Power: 1 x AAA alkaline battery, about 350 hours
- In the box: Soil pH Pen, pH 7.0 and pH 4.0 calibration sachets, KCl storage solution sachet
- Warranty: 1 year
- Bluelab part code: PENSOILPH
Frequently Asked Questions
How is it different from the Bluelab Multimedia pH Meter?
The Soil pH Pen is a one-piece pen with the probe built in and a dibber cap to open the hole. The Multimedia pH Meter pairs a handheld meter with Bluelab's separate spear-tip Leap pH probe on a cable.
Can I push the probe straight into the soil?
No. Always make the hole with the storage cap/dibber first. The probe has a glass bulb that breaks if it is forced into soil or knocked sideways.
Can I use it in nutrient solution as well?
Yes. It is fully waterproof and reads solutions of 0.2 EC and above, so the same pen checks your feed tank and your pots. Rinse the tip between the two.
Does it measure EC or moisture?
No, it reads pH and temperature only. For conductivity and moisture in the same media, Bluelab make the Pulse Multimedia EC/MC Meter.
Works Well With
