Product Description ------------------- Product Description: An EC meter (aka nutrient pen, stick or tester) is an inexpensive and convenient digital tool to instantly check your overall water quality. EC = Electrical Conductivity, which is a measure of the water's ability to conduct electricity. With the push of a button, the EC-3 can tell you your overall water purity level, which will be displayed on the screen in µS (micro-Siemens). The lower the EC level, the purer the water, with 0 µS being pure H2O. The EC-3 is great for checking your tap water quality, or knowing when to change a filter. (The meter does not test for biological contaminants.) The EC-3 is a great tool for drinking water, water filtration and purification, colloidal silver, hydroponics (test your nutrients), aquariums, RO/DI systems, pools and spas, commercial and industrial applications and more. The EC-3 is a rugged model that includes a protective carrying case. This is the world's most popular handheld EC meter for industry professionals. From the Manufacturer --------------------- Handheld Conductivity Tester with Advanced Microprocessor Technology and Built-in Sensor Specs.