Most water filters use either a carbon filter or a reverse osmosis water filter, which can also include a carbon filter. The primary difference is that most reverse osmosis water filters use multiple filter types to remove more contaminants than carbon filters alone. Our pros were impressed with AquaTru Connect's three filter system that removes over 80 contaminants, one of the highest number of contaminants among the water filters we tested. Our pros appreciated that the AquaTru App tells you when the filter needs changing as well as other stats like how many gallons of water you've filtered or the amount of total dissolved solids in the tap and filtered water. The tap water reservoir holds 16 cups of water, so you won't have to refill as often, and the carrying handle makes it easy to go to and from the sink.

TDS stands for total dissolved solids and encompasses 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 the US Geological Survey. In practice, calcium and magnesium deposits in your tap water result in so-called “hard water” that tastes bad and can be actively detrimental to your health at higher concentrations. (Read more about TDS here and here.)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 of 0 is extremely acidic, 7 is considered neither acidic nor basic, and 14 represents an extremely basic substance. Since the minerals that comprise the TDS in tap water increase the alkalinity, we expected the filtration process to decrease the pH of the water. Indeed this did turn out to be the case, and you can see a table of the pH changes below. For our testing, we decided to ramp things up a notch and test water prepared at a concentration similar to that of a swimming 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 results from the water prefiltration and once again, filters such as the ZeroWater substantially outperformed the others. Testing pH changes LifeStraw Home 10-Cup Pitcher: This pitcher was elegant, statuesque, and by far the largest we tested; in fact, it was too heavy and large to fit on the shelves in our refrigerator. And, alas, it took more than 45 minutes for the pitcher to filter enough water to fill the reservoir. Most water filter pitchers remove chlorine to improve the taste of the water, which could also lead to a rise in bacteria in the filtered water. Larq solves this by using UV light to inhibit E. coli and Salmonellafrom building up in the water due to chlorine removal. It filters over 45 contaminants such as microplastics, heavy metals, VOCs, endocrine disruptors PFOA and PFOS, pharmaceuticals and more, which we verified through a review of third-party test data. It has a rechargeable removable wand that powers the UV light, which is visible as the water filters through. Access to safe drinking water is an issue across the globe, and it affects communities in the United States. If you’re not sure about your water quality, the Environmental Working Group (EWG) just updated its Tap Water Database in 2021. It’s free and easy to search, and it has information for all states. Enter your zip code or search your state to find details on your drinking water quality based on EWG standards (which are stricter than those of the government). If your tap water does exceed EWG health guidelines, it may be a good idea to consider buying a water filter.

Filtering needs: Not all tap water has the same contaminants, so your contaminant removal needs may differ based on where you live (i.e. according to your water supply and the age of your plumbing) as well as your personal preference for the taste of your water. We recommend using the EWG Tap Water Database to see what’s in your tap water, but if you're unsure what your water contains, it may be best to have a filter that covers the removal of a broad range of contaminants. The EPA doesn’t regulate all contaminants, but at the minimum, our pros suggest a filter that at least removes heavy metals.Birnur Aral, Ph.D, is the executive director of the Beauty, Health and Sustainability Lab, and she has over a decade of R&D experience. Birnur played a lead role in GH's investigative story Is Your Tap Water Safe? and recently assessed the SafeHome brand DIY water testing kits for the Good Housekeeping Seal. She also helped the brand fine-tune its marketing claims and instruction inserts for its kits, including those for Lead, City Water and Well Water. Once finished, we measured the TDS again and noted the percentage change. This process was repeated for higher and lower TDS concentrations, and our findings indicate that each of the units we tested is very consistent at removing the same percentage of overall TDS from any water passed through it. Testing for chlorine Brita is a name everybody is familiar with for a reason, and their filters will serve you well if that's the direction you choose to go. While not as effective as the ZeroWater, they are affordable, effective and have a respectable service life before requiring replacement. Brita is one of the most well-known water filter brands, so it’s no surprise the brand's Elite water filter did a stellar job in our testing and filtered over 30 contaminants.

With under-the-sink water filters, faucet filters, in-line shower filters and whole-house filters, there’s no need to worry about size or capacity as these instantaneously filter water as it flows through. This small but mighty water filter pitcher improves the taste and clarity of water, plus takes out over 30 contaminants, including chlorine, microplastics, sediment, heavy metals, VOCs, endocrine disruptors, pesticides, pharmaceuticals and E.coli bacteria and cysts, which we verified by reviewing the brand’s third-party lab test data. Most brands offer only plastic pitchers, but LifeStraw has a glass and a plastic option.

How we tested

Zero Water’s innovative two-in-one pitcher allows you to pour out of the spout or to dispense water while sits on on the counter with the push-button spigot at the bottom of the pitcher. The Zero Water 5-Stage system comes with a Total Dissolved Solids (TDS) meter, which indicates the level of dissolved salts and minerals in the water such as calcium, magnesium, sodium, sulfate and more. In our Lab tests, the meter read instantaneously. Plus, it filters out five chemical contaminants, including chlorine, heavy metals and endocrine distruptors such as PFOA and PFOS, according to our verified review of third-party test data. It was one of the fastest filters in our tests, coming in at 38 seconds per cup of water and, according to Brita, the filter lasts about six months before you need to change it. Chief Technologist & Executive Technical Director Rachel Rothman has this water filter pitcher at home and says, “With five thirsty mouths in our house, I like that the filter lasts longer so I’m not constantly changing it, and I enjoy the taste of the water.” Chlorine in your drinking water may sound strange, but it is actually a very common practice for water treatment facilities to add chlorine to the water supply as a disinfectant. This is extremely effective at getting rid of other, nastier contaminants in the water, but the World Health Organization estimates that a concentration of ~0.2-4 ppm is standard for tap water, indicating that at least some is left over after disinfection. Style and size: When choosing a style, keep in mind size versus weight. If you need to save space, opt for a smaller pitcher, which will require more refills. Large-capacity pitchers allow you to refill less, but they can also be cumbersome to carry and pour. If you have the counter space and like to have a large capacity water dispenser, consider a countertop model as these often hold larger amounts of water. The AquaTru water filter dispenser removes over 80 contaminants, one of the highest among the water filters we tested, which earned it one of the top spots in our tests. We verified that it removes contaminants such as chlorine, heavy metals like lead, VOCs, pharmaceuticals, endocrine disruptors and more. In addition, it removes over 90% of fluoride, which some may prefer removed while others may not.