Product Description: A TDS meter (aka ppm pen, nutrient tester, tds stick) is an inexpensive and convenient digital tool to instantly check your overall water quality. TDS = Total Dissolved Solids, which is any salt, metal or mineral in the water. With the push of a button, the TDS-EZ can tell you your overall water purity level, which will be displayed on the screen in ppm (parts per million). The lower the TDS level, the purer the water, with 0 ppm being pure H2O. The TDS-EZ is great for checking your tap water quality, or knowing when to change a filter. (The meter does not test for biological contaminants.) The TDS-EZ is a great tool for drinking water, water filtration and purification, hydroponics (test your nutrients), aquariums, RO/DI systems, pools and spas, and more.

• Economy model that is ideal for end-users. Highly efficient and accurate due to its advanced microprocessor technology.
• Hold Function: saves measurements for convenient reading and recording.
• Auto-off function: the meter shuts off automatically after 10 minutes of non-use to conserve batteries. Display: large and easy-to-read LCD screen.
• Measurement Range: 0-9990 ppm. From 0-999 ppm, the resolution is in increments of 1ppm. From 1000 to 9990 ppm, the resolution is in increments of 10ppm, indicated by a blinking 'x10' image. Fun, translucent blue housing that's very strong and durable.
• TDS-EZ meters are calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver. Includes a TDS chart sticker on the back of the meter that explains TDS values.