Aqua Master Tools P50 Pro2 pH meter with temperature

Measure the pH and temperature of your nutrient solution. Waterproof, floats, and the electrode can be replaced on its own when it wears out.

The Aqua Master Tools P50 Pro2 is a straightforward, solid pH pen. Hold it in your nutrient solution, wait for the reading to settle and read the pH and temperature. The display is black with white figures and you choose whether to read one or two decimals.

What's new in the Pro2

• AAA batteries instead of button cells: cheaper and available everywhere.
• Black display with white figures, easier to read over a dark reservoir.
• One or two decimals, your choice.
• Calibration reminder after 30 days, so you don't forget to recalibrate.

Why a pH pen needs regular calibration

A pH electrode drifts slowly, even when stored well. That's why you calibrate the P50 Pro2 regularly at two points, pH 7.0 and pH 4.0. It's automatic: the pen recognises the solution itself. After a successful calibration an indicator appears that disappears after 30 days, your cue to calibrate again.

An electrode you replace on its own

When the electrode wears out, you replace just the electrode, not the whole pen. Keep the electrode moist with KCl storage solution in the cap. Dried salt crystals around the electrode are normal and not a sign of a fault.

Technical specifications:

• Range: pH 0.0 to 14.0 · temperature 0 to 50 °C
• Resolution: pH 0.1 or 0.01 · temperature 0.1 °C
• Accuracy: pH ± 0.1 · temperature ± 1.0 °C
• Calibration: automatic, 2 points (pH 4.0 and 7.0)
• Temperature compensation: automatic, 0 to 50 °C
• Waterproof: IP67, floats
• Power: 2 x 1.5 V AAA (included)
• Auto power-off: after 8 minutes
• Dimensions: 230 x 43 x 43 mm
• Weight: 132 grams

Frequently asked questions

Do I need an EC meter as well?
If you add nutrients, yes: the P50 Pro2 only measures pH. Add the E50 Pro2 for EC, or choose the P110 Pro2, which does both in one pen.

How often should I calibrate?
With daily use about once a month, and whenever readings look odd. The pen reminds you itself after 30 days.

What if I drop it in the reservoir?
Nothing happens: it is IP67 waterproof and it floats.