Bluelab® pH Pen is the go-to handheld pH meter for professional growers managing nutrient solutions in polyhouse, hydroponic, and soil-based cultivation. Measuring both pH and temperature simultaneously, this compact, fully waterproof instrument delivers instant, accurate readings that help you maintain the optimal pH window (5.5–6.5 for most crops) where nutrient availability is maximized.
Why pH Matters
Nutrient pH is the single most important factor determining whether your plants can actually absorb the fertilizers you provide. Even with perfect NPK ratios, if pH drifts outside the optimal range, nutrients become "locked out" — wasting your fertilizer investment and starving your crops. The Bluelab pH Pen gives you instant visibility into this critical parameter.
Key Features
- Dual Measurement — Reads both pH and temperature simultaneously for complete nutrient assessment
- Double-Junction Probe — More durable and accurate than single-junction probes, with longer calibration stability
- 30-Day Calibration Indicator — Visual reminder ensures you never operate with an out-of-calibration meter
- Fully Waterproof — Rated for complete submersion — no damage from accidental drops in solution tanks
- Backlit LCD — Easy-to-read display in all lighting conditions, including dark greenhouse environments
- Auto Temperature Compensation — Automatically adjusts pH readings for solution temperature
Technical Specifications
| Measurements | pH: 0.0–14.0 (±0.1) | Temperature: 0–50°C (±0.5°C) |
| Probe Type | Double-junction glass pH electrode |
| Display | Backlit LCD |
| Calibration | Simple 2-point (pH 4.0 & 7.0) |
| Waterproof | Yes — fully submersible |
| Battery | Replaceable AAA (included) |
| Auto-Off | Yes — conserves battery |
| Weight | 100g approx. |
