EZ Read Large Display Tank Pool Thermometer and Power Cord, Blue,It is your ideal choice.

Pocket Reservoir Pool Thermometer: A must-have for pool maintenance. Alcohol-based thermometer with large, easy-to-read numbers. Dual Display Reading: Displays both Fahrenheit and Celsius. Maximum Temperature: 120°F (50°C). Greater Accuracy: The convenient pocket reservoir holds water for easy readings outside the pool. Sink Thermometer: The durable plastic body sinks for more accurate readings and withstands daily use and wear. More accurate than a floating thermometer, which takes measurements based on the pool, sun, wind, and ambient air. Easy to Prepare: Large format, 9.5" x 1.5", in 2-degree increments, Celsius and Fahrenheit.