To test these water filter pitchers, we washed each one with mild soap and water, then followed the individual manufacturer instructions for soaking, rinsing or otherwise prepping filters for use.
Testing for TDS (total dissolved solids)
We filled a marked mason jar glass with 16 ounces of tap water and used an Orapxi water quality tester to measure and note the TDS present to see how much was in the water originally and how much had been removed. While the results of my tap water varied slightly each time I filled a fresh glass with 16 ounces the TDS of the water used always read between 47 and 50 ppm, or parts per million. (Read more about TDS here and here.)
Then we poured all 16 ounces into a water filter pitcher, waited for it to filter all the water, poured it into a new glass and took the readings again. For nonalkaline pitchers, you should expect to see a drop in the TDS readings, as impurities and other minerals are removed from the water. We repeated these steps a total of three times on each of the pitchers.
TDS meters are not sophisticated enough to decipher which impurities, nutrients and other minerals each filter manages to remove (or add, in the case of the alkaline pitchers). For that reason, measuring TDS alone as an indicator of water quality has some limitations. But, in general, for a standard filtered water pitcher, we want to see a decrease in the TDS reading. Examples of the most common TDS include “calcium, magnesium, sodium, potassium, bicarbonate, sulfate, chloride, nitrate, and silica,” according to the US Geological Survey.
Measuring water pH
In a previous round of testing, we ran three alkaline water filter pitchers through a pH test — Clearly Filtered, Invigorated Water pH Vitality and Seychelle pH20. All saw an increase in both the pH and the TDS, since they’re designed to add minerals to your water, but the Seychelle saw the biggest pH increase which is why we’ve listed it as the best pitcher to buy if you want to add alkaline to your tap water.
Measuring water taste
This is the least scientific test we’ll run on the water filter pitchers but still an important one. After filtering water with each pitcher, we give the liquid a good old-fashioned taste test. For this latest round of testing, we took sips of each water from each in succession and compared each drink with that of purified bottled water.
Here’s a table of our most recent TDS removal test results. The data represents an average of three test runs for each filter pitcher.
|TDS (% change)|
|Brita Metro Standard||-45.6|