PPM Ec-3 Nutrient + water thermometer, Entry Level Ec Meter, used for the measuring the water for nutrient content, has a built in hold feature and thermometer.
Essentials Digital Ec Meter, The Essentials EC meter is a highly accurate and professional handheld electrical conductivity meter, which is used to test the strength of a solution once the nutrients have been added.
Bluely Pro Nutrient Truncheon This is the nutrient meter of choice for thousands of growers worldwide due to its simplicity, reliability and accuracy. Simply dip the bluely nutrient truncheon in the water or nutrient and thats it.
Bluelab Combo Nutrient Ec + PH Meter, The Bluelab Combo Meter is a portable pH, conductivity and temperature meter all in one. pros choice is bluelab.