|Manufacturer||HM Digital, Inc.|
|Item Weight||1.58 ounces|
|Product Dimensions||0.55 x 0.9 x 5.5 inches|
|Item model number||TDS-4|
|Batteries||2 LR44 batteries required. (included)|
|Is Discontinued By Manufacturer||No|
|Size||Without Digital Thermometer|
|Item Package Quantity||1|
|Temperature Range||1/50 Degrees Celsius|
|Battery Cell Type||Alkaline|
|Average Battery Life||1000 Hours|
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HM Digital TDS-4 Pocket Size TDS Tester Meter with 0-9990 ppm Measurement Range , 1 ppm Resolution, +/- 2% Readout Accuracy
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- This TDS tester is ideal for all water purification applications, wastewater regulation, aquaculture, hydroponics, and colloidal silver
- ATC (Automatic Temperature Compensation) ; Advanced microprocessor technology
- The Sleek design of the TDS-4 is perfect for personal or commercial use
- Alkaline batteries included
- Hold Function: Freeze the measurement to view it out of the water.
- Auto-off function: the meter shuts off automatically after 10 minutes of non-use to conserve batteries
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Product Description: How Pure is Your Water? 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-4 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-4 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-4 is a great tool for drinking water, water filtration and purification, hydroponics (test your nutrients), colloidal silver, aquariums, RO/DI systems, pools and spas, and more.
From the Manufacturer
TDS Tester with Advanced Microprocessor Technology.
Reviewed in the United States on April 21, 2017
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I bought the 342 ppm calibration liquid to double check this meter, I never get readings that are more than 5-10 ppm off. It really is always in calibration and it comes that way from the factory. For me that's accurate enough. But, there are times when I get readings that are off by 50-60 ppm just by retesting the same water after 5 second (it's not from off gassing, this happens on water fresh from my tap AND water in my aquarium that's). Then there are times when I test 4 or 5 times in a row and get readings with only 2ppm variation.
So take this info/review for whatever you think it's worth. This meter WILL come factory calibrated and it almost always gives you relatively accurate readings regardless of water temperature, but it won't ALWAYS give you dead on ppm readings
I wanted to test the rain water one night as it was raining. In haste to get a sample so I could play with my TDS meter, I simply captured some water running out of my neighbor's PVC drain pipe. I expected it to be filthy even though it had rained for a while and must have flushed the pipe. It measured exactly 10 PPM.
I did some cross checking with the tap sample and it read under 170 PPM. Dipped it in the rain water, which now became slightly contaminated, and the reading became 11 PPM. This item certainly works. I would probably start drinking rain water if I had a PH tester and means of capturing rain water cleanly. Just no real space to do so.
I dinged it for lack of a comparison chart, which I found on the web. Really, how much would a plastic card add to the price of this thing? Could also be printed on the back of the unit. Also dinged for not having a Fahrenheit scale.
An official water testing cup would be nice. I used an old semi-translucent liquid detergent cap. They tend to be water repellent so the detergent runs out of the cup. That means less contamination from sample to sample because no water dropletes stick. Just pour and shake.
Over Father's Day weekend I went to my sister's and checked her tap and filtered 'fridge water. Little surprised to find her surburban water readings in the 270 range, or higher. I always felt her water tasted different, but she simply dismissed the results.
I read all the specs for each tester I found and it came down to this TDS-4 and the TDS-EZ. The determining factors were its accuracy and ATC. The TDS-4 has a stated accuracy of +/- 2% as opposed to the +/- 3% of the TDS-EZ. The TDS-4 has ATC (Automatic Temperature Compensation) which comes in handy since water can be different temps. Each had the same hold and auto-off function and read in 1 ppm for the first 999 and 10 ppm for 1000 - 9990.
One disappointment I had with the TDS-4 was that it didn't have a "How pure is your water?" chart on the back like the TDS-EZ. It's not hard to remember what's on the TDS-EZ chart, but would be a nice-to-have. Instead I just remember that 0 to 50 is what my RO system should be at, 50 to 100 are carbon filters, 100 to 200 is hard water, 200 to 400 is average tap water (200 to 300 being marginally acceptable drinking water), and that 500 is the EPA's max level it should be (Source: TDS-EZ chart).
I originally ordered the TDS-4 to test our new RO (reverse osmosis) under counter filtration system (Watts Premier WP-4V). Now for my experience with the TDS-4, when I received the unit from Amazon I immediately tested my RO system first (29 ppm), then my tap (251 ppm), and finally RO water from a local watershop (2 ppm). My RO system was in mid-range of the 0 to 50 acceptable for RO systems, my tap was in the mid-range of acceptable tap levels of 200 to 300, and the water from the watershop was almost pure water. I'm pleased with my RO system compared to the watershop since they have huge filtration systems and the WP-4V takes up less than half of my cabinet under the sink; although, I do wish they tasted identical, the WP-4V tastes good, just not perfect like that from the watershop.
I did another test at my employer who a filter on the drinking water, the result was 221 ppm, I knew it was bad, but expected better because of the filter which I don't know what kind of filter it is. Needless to say I'm bringing in my own water for now on since the water from their tap was 240 ppm.
I ordered the TDS-4 from Amazon Prime and received it in 2 days in perfect condition. I would definitely recommend this to those who want an estimate of what the level of TDS is in their water, it will also come in handy to show the life of our RO filters.
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I tested a cup of filtered water (by ZeroWater) with 5 different TDS meters (1 from ZeroWater). The HM Digital showed twice more than then other 4 meters!
It’s important to know the exact number if you use ZeroWater filters. If 4 products show 5 and HM Digital tells me it’s 6, then that means I should order new filters (which are not cheap!) or risk a little and wait longer - which I’d rather not!!
As a result, I recommend buying 2 or even 3 different products instead of HM Digital which costs the same!!