3-in-1 Water TDS EC Temperature Tester Meter - Exqline Accurate Professional TDS Tester for Domestic Water Testing, Filter Performance, Aquariums, Aquaculture What is TDS?: Total Dissolved Solids (TDS) are the total amount of mobile charged ions, including minerals, salts or metals dissolved in a given volume of water, It is directly related to the purity of water and the quality of water purification systems and affects everything that consumes, lives in, or uses water, whether organic or inorganic, whether for better or for worse. This is a 3-in-1 Water Tester: Professional quality combination TDS tester, TDS EC meter and temperature meter, Measurement Range: Conductivity: 0 -- 9990us/cm; TDS: 0 -- 9999ppm; Degrees Celsius: 0 .1 -- 80 .0; F: 32 .0 -- 176 .0  F; Accuracy:  2%. Easy Use: Press the switch - dig it( the electrode) into test water - press hold button after the numerically stable - take out to read. Nothing could be easier. HOLD automatic locking, SHIFT automatic conversion, 5 minutes Automatic turn-off. Compact Size & Widely Use: Widely use indoor and outdoor, such as domestic water testing, camping or any outdoor exercise, fish farming, plantingetc. Compact size that enable you to take anywhere. Why Should You Measure the TDS Level in Your Water?: The EPA Secondary Regulations advise a maximum contamination level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS. Numerous water supplies exceed this level.Even the best water purification systems on the market require monitoring for TDS to ensure the filters and/or membranes are effectively removing unwanted particles and bacteria from your water.