Aqua Master P50 Pro pH Meter + Temperature

What does the Aqua Master P50 Pro measure?

It measures pH and temperature in liquids like nutrient solutions, hydroponic tanks, runoff, aquariums, ponds, and spas. It does not measure EC, PPM, or TDS. Temperature can be displayed in °C or °F.

What are the pH and temperature ranges?

The P50 Pro reads pH from 0.0 to 14.0 and temperature from 0°C to 50°C. It includes automatic temperature compensation (ATC) to improve pH accuracy during normal temperature fluctuations.

How do I calibrate the Aqua Master P50 Pro?

It uses 2-point auto calibration with fresh pH 7.0 and pH 4.0 buffer solutions (in that order). Always pour into a clean cup—don’t dip into the bottle—and discard used solution after. Calibrate monthly or more often if needed.

Why won’t my P50 Pro calibrate properly?

Common causes include dirty or dried-out electrodes, contaminated buffer solutions, low batteries, or air bubbles on the sensor. Clean the electrode, use fresh buffers, and try again after a short soak if needed.

How do I clean and care for the electrode?

Rinse after every use. If there’s buildup, clean gently with a proper pH electrode cleaner, rinse again, and recalibrate. Avoid rubbing or scraping the sensor. Organics may require more frequent cleaning.

When should I replace the electrode?

If calibration fails, readings drift, or it responds slowly even after cleaning, the electrode likely needs replacing. The P50 Pro uses a user-replaceable electrode—just install carefully and recalibrate afterward.

Is the Aqua Master P50 Pro waterproof?

Yes—it’s IP67 waterproof and designed to float. If the electrode is installed properly and the seal is seated, it remains waterproof even after replacements.

How do I get the most accurate pH readings?

Use a well-mixed sample, submerge the sensor fully, gently swirl to remove bubbles, and wait for the reading to stabilise. Avoid spots near air stones or dosing outlets in your tank.

Why does my pH reading change or drift?

Common reasons include poor mixing, temperature swings, dirty sensors, or air bubbles. Also, pH often changes naturally after nutrient or pH adjusters are added—let it mix before rechecking.

Should I measure pH in the reservoir or a sample cup?

Either works, but using a clean sample cup is more hygienic—especially when testing multiple systems. Just rinse the meter after testing runoff or dirty solutions.

Can the P50 Pro be used to test pH Up/Down directly?

No—never test raw concentrates. Always dilute them in your nutrient mix before testing, or you risk damaging the electrode and getting inaccurate results.

Does the Aqua Master P50 Pro help prevent nutrient lockout?

Yes—by keeping your solution’s pH within the proper range, it helps avoid the imbalances that cause lockout. It won’t fix existing issues but helps you stay in the safe zone.

What batteries does the Aqua Master P50 Pro use?

It runs on three 1.5V AG-13 button cell batteries. It features auto shut-off after about 8 minutes and includes a low-battery warning to help avoid erratic readings.

How should I store the Aqua Master P50 Pro?

Keep the cap on, rinse the sensor after use, and avoid letting salts dry on the electrode. The cap includes a cord so you don’t lose it during regular use—simple habits = longer lifespan.

What’s the best routine for using the P50 Pro accurately?

Rinse → measure in a well-mixed sample → rinse again → cap it → clean when slow → calibrate monthly with fresh pH 7 and 4 buffers. Don’t skip maintenance and trust the numbers blindly.