5-in-1 Digital Water Quality Tester
Theis 5-in-1 Water Quality Tester is a compact, multi-functional device designed to accurately measure five key water parameters: pH, TDS, EC, salinity, and temperature. Ideal for aquariums, swimming pools, hydroponics, and drinking water, it offers fast and reliable readings in a simple, easy-to-use format.
Key Features:
5-in-1 Measurement: Tests pH, TDS (Total Dissolved Solids), EC (Electrical Conductivity), salinity, and temperature in one device.
Wide Measurement Ranges:
- pH: 0.00 to 14.00
- TDS: 0 to 19999 ppm
- EC: 0 to 19999 µS/cm
- Salinity: 0 to 19999 ppt (0.0%–100%)
- Temperature: 0–60°C (32–140°F)
High Accuracy: Built-in temperature sensor automatically compensates readings for increased precision.
Backlit LCD Screen: Displays multiple parameters clearly at once for quick assessment.
Portable and Durable: Made of ABS plastic, lightweight (95g), and compact (150 × 29.5 × 145 mm).
Power Efficient: Operates on 4× LR44 batteries for long-lasting use.


Applications:
This water tester is suitable for a variety of environments, including:
- Window Cleaning water purity
- Cleaner Testing
- Aquariums and fish tanks
- Swimming pools and spas
- Hydroponic systems
- Drinking water analysis
- Laboratory or industrial water testing
Product Details:
- Model: M51
- Material: ABS
- Display Type: LCD with backlight
- Power Source: 4 × 1.5V LR44 batteries
- Net Weight: 95g
- Color: Green and White (custom colors available)
Summary:
With its sensitive probe, wide measurement range, automatic temperature compensation, and simple user interface, the M51 5-in-1 Water Quality Tester is a reliable tool for monitoring water quality in a wide variety of applications.

