Aqua Master Tools P50 Pro2 pH & Temperature Meter — IP67 Waterproof Pen Meter
AMT-METER-PH-P50PRO2
Pairs well with
The Aqua Master Tools P50 Pro2 is a no-fuss, high-accuracy pH and temperature pen meter built for daily use in the grow room. Whether you're checking reservoir pH before a feed or confirming run-off temperature, this thing delivers a clear, reliable reading in seconds — IP67 waterproof, floatable, and powered by standard AAA batteries so you're never hunting for obscure button cells mid-grow. The Pro2 is the upgraded version of Aqua Master's popular P50 Pro, with a sharper black-and-white display, selectable 1 or 2 decimal precision, and a 30-day calibration reminder built right in.
Specifications
- Store the meter upright with KCl storage solution in the cap. A dry electrode drifts and wears out faster.
- Before first use, soak the tip in tap water for 12 hours to properly hydrate the glass membrane.
- Use the 0.01 resolution setting when dialling in critical pH windows — 0.1 is fine for routine checks.
- Recalibrate with fresh buffer solution at least once a month, or whenever the 30-day reminder triggers.
- Always rinse the electrode with distilled or RO water between measurements to avoid cross-contamination.
- The meter ships pre-calibrated, but calibrate it yourself before the first grow cycle reading for full accuracy.
How to Use the P50 Pro2
Pairs Well With
One half of your 2-point calibration kit. Use this with the 7.0 buffer every 30 days to keep the P50 Pro2 reading accurately.
Hy-gen pH 7.0 Buffer SolutionThe neutral reference point for 2-point calibration. Always calibrate 7.0 first, then 4.0, for best accuracy across the grow range.
pH Up & Down by Growth TechnologyOnce your meter tells you where pH sits, these adjust it. Fast-acting and highly concentrated — a little goes a long way.
EC Meters & PensThe P50 Pro2 covers pH and temp. Add an EC pen alongside it to nail nutrient strength — the two together give you the full picture.
Frequently Asked Questions
What is the difference between the P50 Pro and the P50 Pro2?
The Pro2 adds three key upgrades over the original P50 Pro: AAA batteries instead of button cells (easier to replace, longer life), a black display with white characters for significantly better readability under grow lights, and selectable 1 or 2 decimal pH precision. It also includes a 30-day calibration reminder. The core measurement range and accuracy specs are the same.
Does the P50 Pro2 measure EC or PPM?
No — the P50 Pro2 measures pH and temperature only. It does not read EC, PPM, or TDS. If you need EC alongside pH, look at the Aqua Master P110 Pro2 combo pen, which measures all three parameters in one device.
Is the P50 Pro2 suitable for measuring nutrient solution run-off?
Yes — the P50 Pro2 works well for run-off pH checks. Collect your run-off sample in a container, dip the meter in, and read the result. Just make sure to rinse the electrode with distilled water between your reservoir reading and your run-off sample so you don't carry over contamination.
How often should I calibrate the P50 Pro2?
At minimum, calibrate once per month — the meter will remind you after 30 days. For critical grows or high-value crops, calibrating weekly is not overkill. pH electrodes drift gradually with use, and a miscalibrated meter is worse than no meter at all because it gives you false confidence.
Can I replace the electrode myself?
Yes — the electrode on the P50 Pro2 is user-replaceable with no special tools required. This is one of the main reasons to choose an Aqua Master meter over cheaper alternatives that require you to bin the entire device when the probe wears out. Replacement electrodes are available separately.
What buffer solutions do I need to calibrate the P50 Pro2?
You need pH 4.0 and pH 7.0 buffer solutions for the 2-point calibration. These are sold separately — we stock Hy-gen and Bluelab calibration solutions in-store and online. Always use fresh buffer solution from a sealed bottle; used or old buffer gives inaccurate calibration points.
What warranty does the P50 Pro2 come with?
The meter itself is covered by a 1-year warranty against defects in materials and workmanship from the date of consumer purchase. The electrode carries a separate 6-month warranty. Warranty requires proof of purchase. Physical damage, dirt ingress from misuse, and damage from third-party parts or unauthorised repairs are not covered.
Stop Guessing. Start Measuring.
The P50 Pro2 is the meter growers keep coming back to — waterproof, readable, and built to last longer than a single season. Grab one and take pH out of the guesswork column for good.