The most common way to improve home water quality is to use a water filter pitcher. Such filters enjoy unflagging popularity due to their very low price, ease of use and wide availability. But do these advantages go hand in hand with effectiveness in removing impurities from water?
The creators of Project Farm tried to answer this question on their YouTube channel. The YouTubers from this channel test the effectiveness of various products. Consequently, they decided to focus on popular and widely available water filtration devices available in the US. Among them were water filter pitchers.
The first task set for the water filter pitchers was to filter ordinary tap water. To measure effectiveness of the water treatment process, the project creators used a TDS (Total Dissolved Solids) sensor. It indicates the total amount of dissolved substances in the water. It is worth noting that this sensor provides quantitative information, not qualitative. Thus, the TDS readings include both unwanted contaminants and valuable minerals added together.
How did the water filter pitchers from popular brands perform? Only one of the five devices delivered completely purified water. Two filter pitchers scored 233 and 234 TDS. That was not at all impressive considering that a homemade filter made of sand and activated carbon achieved a similar result (237). Surprisingly, two filter pitchers delivered “purified” water at almost the same level (253 and 260 TDS) as unfiltered tap water (259 TDS)!
The second task was to purify well water additionally tainted with red coloring (TDS of 364). As with the first test, one of the pitchers completely purified the water of dissolved substances and restored the transparent color. The other pitchers did better or worse (TDS: 221, 265, 302, 335). It is worth mentioning that the home-made filter scored 248, which outperformed the products of leading manufacturers.
In the third test, the water filter pitchers were tasked with filtering distilled water contaminated with iron. Again, only one of the five filters performed this task perfectly. The second filter degelatinized the water with impressive efficiency (10 ml/l iron remained in it). The others did less well (50 or 100 ml/l), but it’s fair to say that compared to other filtration devices (except for the reverse osmosis system, which purified the water effectively every time) they were the most effective.
Admittedly, the tests were not conducted in laboratory conditions. However, the test results certainly raised many interesting questions. So do water filter pitchers solve all the problems? Most of them unfortunately do not. Although it’s worth noting that one such filter, thanks to its advanced composition, managed to purify water as effectively as a reverse osmosis system. This is an amazing achievement.
Unfortunately, other water filter pitchers have shown little or no effectiveness. This low efficiency can be attributed to two factors. One is the short contact time between the water and the filter. The other is the composition of the cartridge. Standard pitcher cartridges mainly contain activated carbon. The latter, despite the fact that it has great absorptive properties, is not able to remove such contaminants as microorganisms, ammonium ions and ammonia, nitrates and nitrites.