Aqua Master P50 pH & Temperature Meter - Waterproof Dual-Function Handheld Tester
Best for: Growers who want an accurate, waterproof pH and temperature meter without paying for a lab-grade professional instrument.
Our thoughts
A genuinely useful two-in-one meter - pH and temperature off the same probe, in a waterproof housing that can handle getting splashed or dropped in the reservoir without dying on you. Comes calibrated out of the box, which matters more than people expect.
The P50 is a handheld digital meter from Aqua Master Tools that measures both pH and temperature from a single probe, switching between the two readings at the press of a button. It covers a pH range of 0.0 to 14.0 with a resolution of ±0.1 pH, and a temperature range of 0°C to 50°C with ±0.5°C accuracy. The housing is IP67 rated, so it's fully protected against dust and can survive brief submersion, which matters for a tool that's going to spend its life around nutrient tanks and reservoirs.
It comes fully calibrated from the factory and ships with batteries included (3 x AG13 button cells), so it's ready to use straight out of the box. Automatic temperature compensation keeps pH readings accurate as solution temperature changes, and the meter auto-calibrates against a 2-point reference (pH 4.0 and 7.0) when you do need to recalibrate. An auto power-off after 8 minutes of inactivity helps preserve battery life.
How it compares
Sits in the mid-range of handheld pH/temp meters.
- More affordable than premium probe-based meters like the Bluelab Combo Meter or Milwaukee MW102, which add EC/conductivity measurement alongside pH and temperature
- The IP67 waterproof rating is a genuine advantage over cheaper pH pens that aren't rated for splashing or submersion
- A step up from basic pH-only test strips or entry-level pens, without the cost or bulk of a full benchtop lab meter
You're paying for genuine waterproofing and dual pH/temperature function at a price well below the premium multi-parameter meters.
Usage guidance
Simple to use day to day, but a little care keeps readings accurate long term.
Taking a reading
Submerge the probe tip in your solution, wait for the reading to stabilise, and switch between pH and temperature using the meter's buttons.
Calibration
Recalibrate roughly once a month using pH 4.0 and 7.0 calibration solution kept at 25°C, since calibrating at the wrong solution temperature will throw off accuracy.
Storage
Store the probe with its cap on and slightly moist (a few drops of storage or calibration solution) rather than letting it dry out between uses, which extends electrode life.
Battery care
The auto power-off after 8 minutes helps, but replace the 3 x AG13 batteries as soon as readings start drifting or the display dims.
Technical specifications
- Measures: pH and temperature
- pH range: 0.0 - 14.0 pH
- pH accuracy: ±0.1 pH
- Temperature range: 0°C - 50°C (32°F - 122°F)
- Temperature accuracy: ±0.5°C
- Waterproof rating: IP67
- Dimensions: 220 x 40 x 40mm
- Weight: Approx. 102g
- Power: 3 x AG13 button cell batteries (included)
- Calibration: 2-point auto calibration (pH 4.0/7.0), ships pre-calibrated
- Auto power-off: After 8 minutes of inactivity
Who this is for
- Growers who want a reliable, waterproof pH meter without buying a full multi-parameter unit
- Anyone testing pH and temperature around reservoirs, pools or ponds where splashing is inevitable
- Growers upgrading from basic pH test strips or a non-waterproof pen
- Not a fit if you also need EC/conductivity in the same device - look at a combo meter for that
Our take
A solidly specified, genuinely waterproof pH and temperature meter that covers the two readings most growers check daily. It comes ready to use and the accuracy is in line with meters costing considerably more.
One we sell a lot of for growers who want dependable daily pH checks without overspending on a professional multi-meter.
