Bluelab pH Pen – Accurate pH & Temperature Meter for Hydroponics

Stop Guessing. Start Growing with Confidence.

Your plants can't tell you when the pH is off — but the Bluelab pH Pen can. Whether you're a home grower or a seasoned hydro enthusiast, getting your pH right is the single most important thing you can do for healthy, high-yielding plants. The Bluelab pH Pen makes it effortless.

Why pH Matters for Your Grow

Even with the best nutrients in the world, your plants can't absorb them if the pH is out of range. Too acidic or too alkaline, and your crop suffers — stunted growth, yellowing leaves, and wasted money on nutrients that never reach the roots. The Bluelab pH Pen gives you instant, accurate readings so you can correct your solution before problems start.

Key Features

• Precise pH readings in 0.1 increments — catch imbalances before they affect your crop
• Built-in temperature measurement in °C or °F — because temperature affects nutrient uptake too
• Double-junction pH probe for reliable, long-lasting accuracy
• Simple 2-point calibration with a 30-day reminder so you're always measuring correctly
• Bright backlit display — easy to read in any grow room lighting
• Waterproof and floats — no stress if it slips into your reservoir
• Compact handheld design — fits in your pocket, goes wherever you grow

Built in New Zealand. Trusted by Growers Worldwide.

Bluelab has been the go-to brand for serious growers for decades. The pH Pen is one of their best-selling tools — relied on by hobbyists and commercial operations alike. When you pick up a Bluelab, you're getting a tool that's been refined through real-world growing experience.

What's in the Box

• 1x Bluelab pH Pen
• 1x pH 7.0 Calibration Solution sachet (18ml)
• 1x pH 4.0 Calibration Solution sachet (18ml)
• 1x KCl Storage Solution sachet
• 1x AAA alkaline battery (installed)

Technical Specifications

• pH Range: 0.0 – 14.0 | Resolution: 0.1 | Accuracy: ±0.1 at 25°C
• Temperature Range: 0–50°C / 32–122°F | Accuracy: ±1°C / ±2°F
• Solution Requirement: 0.2 EC and above
• Power: 1x AAA alkaline battery
• Warranty: 1-year limited warranty

Pro Tip: Pair It with the Bluelab Conductivity Pen

For a complete picture of your nutrient solution, pair your pH Pen with the Bluelab Conductivity Pen to also measure EC/ppm levels. Together, they give you full control over your feed — available at Hydro Grow Sydney.