The best water filter pitcher for 2024

As mentioned earlier in this article, there are a number of contaminants worth removing from tap water. The team here at our lab settled on three primary tests to compare the effectiveness of these filters: TDS, pH and chlorine. Before we began the actual testing process, each jug was removed from its packaging, cleaned and then prepared according to the manufacturer’s instructions. This is very important, because most of these filters use activated carbon filtration, which will deposit sediment in the first batches of water you filter if it is not cleaned beforehand.

Testing for TDS

TDS stands for Total Dissolved Solids and includes many different impurities present in water. Examples of the most common TDS include “calcium, magnesium, sodium, potassium, bicarbonate, sulfate, chloride, nitrate, and silica,” according to US Geological Survey. In practice, calcium and magnesium deposits in your tap water lead to so-called “hard water” that tastes bad and can be harmful to your health in higher concentrations. (Read more about TDS from the EPA and USGS.)

We started the TDS testing by mixing an 8 gallon bucket of tap water, measured at 220 ppm TDS, with table salt until we reached a TDS reading of 300. Generally, 50-150 TDS is considered the ideal range for drinking water. We used an Orapki water quality tester for these measurements and since the ZeroWater filter also includes a TDS tester, all TDS readings were verified on both devices. Once we established our control source, we measured 1 liter of 300 TDS water into each of the water filter jugs and allowed the full amount to pass through the filter.

When we were done, we measured the TDS again and recorded the percentage changes. This process was repeated for higher and lower TDS concentrations, and our findings show that each of the units we tested was very consistent in removing the same percentage of total TDS from any water passing through it.

Chlorine testing

Chlorine in your drinking water may sound strange, but it is actually a very common practice for water treatment plants to add chlorine to the water supply as a disinfectant. This is extremely effective at removing other, worse contaminants in the water, but estimated by the World Health Organization that a concentration of ~0.2-4 ppm is standard for tap water, indicating that at least some remains after disinfection.

For our testing, we decided to step things up a notch and test water prepared at a concentration similar to that of a pool – 10 ppm chlorine. This gave us a clear indication of the changes after filtration. Once again, each filter was tested with 1 liter of solution and compared to the results of pre-filtration water and once again, filters like ZeroWater far outperformed the others.

Testing for pH changes

Finally, during TDS testing, we also measured the change in pH. pH stands for “potential of hydrogen” and is used to quantify the acidity of a substance. A pH value of zero is extremely acidic, seven is considered neither acidic nor basic, and 14 represents an extremely basic substance. Since TDS-containing minerals in tap water increase alkalinity, we expected the filtration process to lower the pH of the water. It turns out that this was indeed the case, and you can see a chart of the pH changes below.

Here is a table of our latest TDS removal test results. Data represent the average of three test runs for each filter thrower.