Bluelab pH Pen – Waterproof 0-14 pH Meter

Lab-grade pH accuracy in a waterproof pen that floats

The Bluelab pH Pen brings the accuracy growers rely on across the Bluelab range down into a compact handheld meter. It reads pH across the full 0.0 to 14.0 range to +/-0.1, uses automatic temperature compensation so readings stay honest as your reservoir warms and cools, and is fully waterproof and floats - so an accidental drop in the tank is no drama. A backlit display keeps it readable under dim grow-room lighting.

Fixing nutrient lockout caused by pH drift

Even a perfectly mixed feed becomes unavailable to the roots once pH drifts outside the target band, showing up as yellowing, poor uptake and slow growth that looks like a nutrient shortage but isn't. Accurate, regular pH checks catch that drift early - in hydro reservoirs and in soil or coco run-off - before it costs you a harvest.

How to Use

• Before first use, calibrate with the supplied pH 7.0 and pH 4.0 sachets
• Recalibrate every 30 days or when the on-screen reminder prompts you
• Dip the probe fully into the solution, swirl gently and wait for the reading to stabilise
• Rinse after use and store the probe tip damp in storage solution, never dry
• Replace the single AAA battery when the display dims