{"product_id":"hm-digital-tds-3-handheld-tds-meter","title":"HM Digital TDS-3 Handheld TDS Meter with Carrying Case","description":"\u003cp\u003eThe \u003cstrong\u003eHM Digital TDS-3\u003c\/strong\u003e is the classic pocket TDS meter: dip it, wait a moment, and read your water's total dissolved solids from 0 to 9990 ppm on a clear digital display, with a built-in thermometer and automatic temperature compensation. It is the fastest way to check that your RO\/DI unit is still making 0 ppm water, to know when the DI resin is spent, and to compare tap water before and after filtration. Every meter ships factory calibrated with a black vinyl carrying case and belt clip. It pairs naturally with our \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/icecap-4stage-rodi-75gpd\"\u003eRO\/DI systems\u003c\/a\u003e and the rest of our \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/water-testing\"\u003ewater testing kits\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eWhy Test TDS\u003c\/h3\u003e\n\u003cp\u003eTotal dissolved solids is the quickest health check for purified water. Fresh RO\/DI water should read 0 ppm; once the number starts climbing, the DI resin is exhausted and the water is carrying minerals, silicates and other dissolved solids into your tank. A ten-second reading tells you whether to trust the water you are about to use for top-off, salt mixing or water changes.\u003c\/p\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide range:\u003c\/strong\u003e 0 to 9990 ppm, with 1 ppm resolution up to 999 ppm and 10 ppm resolution above that (the display shows an x10 icon).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccurate and compensated:\u003c\/strong\u003e plus or minus 2% accuracy with automatic temperature compensation from 1 to 50 degrees C, so a cold sample and a warm sample read the same.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in thermometer:\u003c\/strong\u003e a second button switches the display to water temperature in 0.1 degree C steps.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHold function:\u003c\/strong\u003e lock the reading on screen so you can pull the meter out of a reservoir or filter housing and read it in good light.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAuto shut-off:\u003c\/strong\u003e powers down after 10 minutes to protect the two included LR44 button cells.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReady out of the box:\u003c\/strong\u003e factory calibrated with a 342 ppm NaCl solution, no calibration fluid or storage solution needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCarrying case with belt clip:\u003c\/strong\u003e the vinyl case keeps the probe protected in a fish-room drawer or on your belt.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eHow to Use\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eRemove the cap and press ON.\u003c\/li\u003e\n\u003cli\u003eDip the probe into the sample no deeper than the maximum immersion line and stir gently to shake off air bubbles.\u003c\/li\u003e\n\u003cli\u003eWait for the reading to settle, then press HOLD to freeze it if you need to lift the meter out to read it.\u003c\/li\u003e\n\u003cli\u003ePress TEMP to check the water temperature. Rinse the probe with clean water, shake it dry and replace the cap.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eSpecifications\u003c\/h3\u003e\n\u003ctable style=\"border-collapse:collapse;width:100%;max-width:640px;font-size:0.95em;\"\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eHM Digital TDS-3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eTDS range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e0 to 9990 ppm (mg\/L)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eResolution\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e1 ppm (0 to 999 ppm), 10 ppm (1000 to 9990 ppm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eAccuracy\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e±2% (0 to 5000 ppm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eTemperature range\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e0 to 80 degrees C, 0.1 degree resolution (Celsius only)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eTemperature compensation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eAutomatic, 1 to 50 degrees C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eEC to TDS factor\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eNaCl (average 0.5)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eFunctions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eHold, temperature, auto-off after 10 minutes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003ePower\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e2 x 1.5 V LR44 button cells (included), about 1000 hours\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e6.1 x 1.25 x 1 in (15.5 x 3.1 x 2.3 cm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e2.7 oz with case, 2 oz without\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eCalibration\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eFactory calibrated with 342 ppm NaCl solution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003e\u003cstrong\u003eWater type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #ddd;padding:6px 10px;vertical-align:top;\"\u003eFreshwater, tap and RO\/DI water (see FAQ for saltwater)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eHM Digital TDS-3 handheld TDS meter\u003c\/li\u003e\n\u003cli\u003eBlack vinyl carrying case with belt clip\u003c\/li\u003e\n\u003cli\u003e2 x LR44 button cell batteries (installed)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eRecommended Pairings\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/icecap-4stage-rodi-75gpd\"\u003eRO\/DI systems\u003c\/a\u003e, the water this meter is made to check\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/dow-filmtec-100-gpd-ro-membrane\"\u003eDow Filmtec RO membrane\u003c\/a\u003e, when the post-membrane reading starts to climb\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/hm-digital-trm-1-triple-inline-tds-meter\"\u003eHM Digital TRM-1 Triple Inline TDS Meter\u003c\/a\u003e, for a permanent readout on every stage of your RO\/DI\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/squeakys-aquatics-adjustable-ro-float-valve\"\u003eAdjustable RO float valve\u003c\/a\u003e, to automate your RO\/DI reservoir\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/squeakysaquatics.com\/products\/saltwater-refractometer-with-calibration-fluid-bundle\"\u003eRefractometer\u003c\/a\u003e, for measuring salinity in saltwater tanks\u003c\/li\u003e\n\u003cli\u003eMore \u003ca href=\"https:\/\/squeakysaquatics.com\/collections\/water-testing\"\u003ewater testing kits\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin:14px 0 4px;font-size:1.05em;font-weight:600;line-height:1.25;border-left:4px solid #666;padding-left:8px;\"\u003eFAQ\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eCan I measure my saltwater tank with it?\u003c\/strong\u003e No. Natural seawater is around 35,000 ppm, far beyond the 9990 ppm range, so the TDS-3 is for freshwater, tap, top-off and RO\/DI water. Use a \u003ca href=\"https:\/\/squeakysaquatics.com\/products\/saltwater-refractometer-with-calibration-fluid-bundle\"\u003erefractometer\u003c\/a\u003e for salinity.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat should my RO\/DI water read?\u003c\/strong\u003e 0 ppm out of the DI stage. When it reads 1 to 2 ppm or more, the resin is exhausted and it is time to change it. Checking the water after the membrane but before the DI tells you how hard the resin is working.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it need calibration?\u003c\/strong\u003e It arrives factory calibrated and holds calibration well. If you want to verify it, HM Digital calibration solution and a small screwdriver adjust it in seconds.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I leave it in the water?\u003c\/strong\u003e No. Dip it only to the immersion line, take the reading and rinse it off. It is not designed to be submerged or left in a reservoir.\u003c\/p\u003e","brand":"HM Digital","offers":[{"title":"Default Title","offer_id":49314736505051,"sku":"TDS-3","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0767\/5209\/3403\/files\/200034-TDS-Meter-Handheld-TDS-3-a_1.jpg?v=1789557190","url":"https:\/\/squeakysaquatics.com\/products\/hm-digital-tds-3-handheld-tds-meter","provider":"Squeaky's Aquatics","version":"1.0","type":"link"}