Measuring TDS in Drinking Water (Total Dissolved Solids)

I purchased a TDS Meter, and subsequently purchased a Zero Water Pitcher/Filter, and it comes with a TDS Meter.

I’m not an expert on TDS Meters, I am new to this, and I am experimenting and writing about it. Here is a link worth seeing.

What Is TDS – How They Work and What They Measure

This, from the Web Page, disagrees significantly with the labeling on the back of the Meter I purchased.


Are total dissolved solids safe?

The EPA regulates TDS in municipal water supplies, but they set no upper limit, only recommendations. Levels lower than 300 mg/L are excellent and reflect the presence of beneficial minerals like potassium. Water with readings between 300 – 900 mg/L is safe but may have a bitter or metallic taste. TDS level greater than 900 mg/L signal probable contamination and should be investigated.

Tentatively, I have measured the TDS of the water in my house, and have found the readings below. I used a small Glass to measure in, to limit the volume of Water, I started with Distilled Water, and measured the TDS in the Distilled Water, and after each measurement I rinsed the Glass with Distilled Water to assure that Solids from one test did not show up in another.

Rear of TDS Meter

The 2nd set of readings below were taken on a subsequent day, not all categories have had 2 readings yet. 

Distilled Water TDS = 1 ppm / 1 ppm

Filtered Water at the Kitchen Sink = 202 ppm / 235 ppm

Unfiltered Water at the Kitchen Sink = 188 ppm / 214 ppm

Brita in the Bathroom, Filter changed a week or so before test = 154

Bathroom Sink Faucet Water = 198

Zero Water Pitcher Taken from the Unfiltered Kitchen Sink Water = 2 ppm

Why is the Filtered Water in the Kitchen so high in TDS? We use this Counter Top Filter that has a Diverter for the water from the Faucet Aerator to the Filter Housing, and there is a Water Spout Tube on the other side of the Filter Housing.

APEX RF-1050 Alkaline Filter Cartridge

  • Removes Chlorine taste and odor, Heavy Metal and controls Microorganisms in your drinking water.

  • Hydrates your body while adding minerals that our body does not produce such as calcium, magnesium, potassium and sodium to name a few.

APEX Countertop Drinking Water Filter – Alkaline

  • Advanced 5-stage alkaline drinking water purification system easily connects to any standard faucet. All hardware included.

  • Removes Chloramine, Odors & Residual Chlorine up to 95% with Granular Activated Carbon & KDF process media while adding Calcium, Magnesium, Potassium with Alkaline Beads & Calcite media.

  • Removes Arsenic, Cadmium, Chromium, Mercury, Lead, Antimony, Selenium, Aluminum, Copper, Iron & Manganese with KDF process media.

  • Removes up to 99.9% of Escherichia coli.

  • Each filter individually wet tested and sanitized.

  • Accepts all standard 10-inch replacement filter cartridges.

  • Neutralizes acid in your bloodstream while boosting metabolism, helping your body absorb nutrients more effectively.

  • Filter cartridge life: approximately 750 Gallons.

In Brief:

It Removes: Arsenic, Cadmium, Chromium, Mercury, Lead, Antimony, Selenium, Aluminum, Copper, Iron & Manganese to an Unspecified Level, Removes up to 99.9% of Escherichia coli, and Chloramine, Odors & Residual Chlorine up to 95% (not sure if the 95% is tied to Residual Chlorine or Chloramine, Odors & Residual Chlorine).


It Adds: Calcium, Magnesium, Potassium, while helping to balance the pH of water, making it alkaline to better suit the body chemistry.

I’m not sold on removing everything to make the water more natural. I am intrigued by the ZeroWater Pitcher/Filter, but it has a 20 to 40 Gallon Life Expectancy for my area (the Counter-Top Water Filter lasts for about 750 Gallons), yet the ZeroWater in the video linked to below removed Food Coloring from the water, indeed a significant task.

One job, years ago, we had a Water Distillation Machine in the Chemistry Lab. Truthfully, I’m not sure why, maybe a vestige to older days of Wet Chemistry, maybe it was used in the modern equipment that we had for Dry Chemistry analysis. But after or in addition to being Distilled, it was De-Ionized. One of the workmen from the plant used to come into the lab and drink it, on occasion. The supervisor would watch him and remark to us how stupid it was, since it pulls valuable minerals from the person’s system. I was never sure why the supervisor just didn’t tell him to stop drinking it.

If the ZeroWater removes all of the minerals, I am not sure if it would similarly draw out minerals from the person drinking it or if it would have to be De-Ionized to do so. ZeroWater claims that with the TDS Removed, the water is more available to Animal and Plant cells in terms of absorption. Early in our evaluation of it, the ZeroWater tastes good, and will be something my wife and I will be using (already bought 5 Filters), but not exclusively, we still will use the Counter-Top Filter System that also adds Minerals to the Water (coffee, cooking additions, and I drink 50% of the Counter Top Filtered Water and 50% Zero Water).

From the article on TDS Meters, the following:

But meters are non-selective, meaning they read only total levels of dissolved solids — they don’t measure specific contaminants. They’re also not sensitive enough to detect uncharged or low-charged ions like lead, pesticides, herbicides, petroleum products and trace pharmaceuticals. If you’re worried about select toxins, it’s like knowing there are fish in your pool without knowing if you’re swimming with guppies or Great White sharks.

TDS Meter On - Front - Card

At this point, I’d say invest in a TDS Meter, Experiment with your water (do not immerse the Meter Tip too Deeply, the Meter IS NOT WATERPROOF), read and understand the article on TDS Meters (linked above), realize the Limitations on the Test Technique, realize the Benefits, and Consider a Counter-Top Filter (or Under-Counter Filter, we used to have that, the Kitchen Sink Spray Head was replaced with a Drinking Faucet), or Filtered Water Pitchers such as ZeroWater, Brita, Pur, or other suitable model. If you don’t have to drink it, i.e. Chemicals, you are better off not doing so.

TDS-EZ Water Tester | Review | Amazon Products:

Best Water Filter? Brita, ZeroWater, PUR, Berkey, Aquaphor, AquaTrue


Author: Dr-Artaud

A Doctor that is not a Doctor, but named after a character in the movie "No Such Thing", as is the Avatar.

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