Although the city water in your home may be safe to drink, it could contain harmful chemicals that are unpleasant-tasting or even unhealthy. A good water filter helps solve those problems by removing heavy metals, pesticides, chlorine, sediment, and other things you don’t want lurking in your glass of drinking water.
Today’s water filters come in various forms, including gravity filter pitchers, reverse osmosis systems, countertop filters, and under-sink filters. Some even treat all the water in your home. Although they may take different forms, they all use filtration methods, such as a carbon filter, membrane, ion exchange technology, or ultraviolet light, to remove contaminants.
If the water in your home needs further purification, then read on to learn more about what goes into the best water filters and learn why the models below are some of the best in their class.
- BEST OVERALL: Brita Standard 18 Cup UltraMax Water Dispenser
- BEST BANG FOR THE BUCK: ZeroWater 10 Cup Water Filter Pitcher
- BEST WHOLE HOUSE: iSpring WGB32B 3-Stage Whole House Water Filtration System
- BEST UNDER SINK: Waterdrop 10UA Under Sink Water Filter System
- BEST COUNTERTOP: APEX Quality Countertop Drinking Water Filter
What to Consider When Choosing the Best Water Filter
Water filters come in a wide variety of shapes and sizes, which can make choosing one a confusing process. Understanding more about the different options available will help you decide which one is right for your home.
- Water filter pitchers: Water filter pitchers use a carbon filter to remove contaminants from water. They have a basin at the top of the pitcher to fill with tap water. Gravity makes the water run through the filter, filling the lower part of the pitcher in about 10 minutes. These pitchers are not only the most affordable water filtration option, they’re also easy to use.
- Faucet attachments: This type of filter attaches to a designated faucet and treats the water as it passes through, purifying it for drinking and cooking. These units are easy to install and are relatively inexpensive.
- Refrigerator water filters: This type of filter fits inside your refrigerator, filtering the water that goes into the water dispenser and ice maker. They use charcoal filters to purify the water and are easy to replace, though they can be costly. If your refrigerator uses a water filter, make sure to purchase the correct replacement filter for your model.
- Under sink: True to their name, an under-sink water filter installs below the sink, treating the water before it reaches the faucet. These models may feature multiple filter stages, removing more contaminants than other types of filters. They can be a little more complicated to install, and the replacement filters typically cost more.
- Countertop: A countertop water filter typically attaches to an existing faucet, which supplies water to a small basin. The filter has a small faucet that draws from the basin for drinking water. These units are easy to install but take up countertop space and use visible hoses that attach to the kitchen faucet’s aerator.
- Portable: Portable water filtration systems, often used by campers and backpackers, consist of a hand-operated pump that draws water into one end and pushes it through a series of carbon and microfiber filters before expelling purified water at the other end.
- Shower filters: Unlike other filters, which are focused on purifying water for drinking, shower filters purify water for bathing. They remove chlorine, bacteria, minerals, and other impurities that can lead to dry skin and damaged hair. These filters are compact and easy to install.
- Whole house: Unlike other water filtration systems that focus on a single faucet or fixture, whole house filters connect to the main water supply as it enters the home, filtering all the water your home uses, including every faucet as well as dishwashers and washing machines. This is a cost-effective way of filtering all the water coming in to a home.
Water filters use a variety of methods to remove impurities from water, including one of the most common, carbon filtration. This type of filtration uses carbon’s porous consistency to absorb water and remove contaminants. It’s especially effective at removing chlorine, pesticides, and solvents. However, it’s not particularly effective at removing heavy metals, such as nitrates, sodium, and fluorine, water.
Reverse osmosis filtration uses a semipermeable membrane that allows water molecules to pass through it while preventing impurities from passing through. Reverse osmosis systems use multiple filters, making them effective at removing chemical contaminants like copper and lead and hard metals, such as calcium, arsenic, and mercury, but they will not remove certain herbicides and pesticides. Because they use multiple filters, reverse osmosis systems require strong water pressure to force the water through the system’s multiple filters and membranes.
Ultraviolet filters pass water through a chamber flooded with UV rays. This effectively kills off bacteria, parasites, and viruses; however, it won’t remove mineral contaminants, such as lead, calcium, and arsenic, or pesticides and herbicides.
Gravity water filters work by filtering water as it passes through a filter to drop from the upper basin of a pitcher to the lower basin. They include charcoal to filter out harmful chemicals and ion exchange resin that captures heavy metals. The best gravity filters remove contaminants such as lead, chlorine, pesticides, and even heavy metals.
Mixed media filtration systems use multiple types of filtration in a single cylinder or container. Filters ranging from gravity pitchers to reverse osmosis systems feature multiple stages to remove different kinds of contaminants.
Most filtration systems don’t require access to power. Gravity filters use gravity, requiring no additional power, while faucet, reverse osmosis, counter, and under-sink systems use the power of water pressure. Some of these systems need a minimum amount of water pressure to work correctly.
Water Quality and Contaminants
While your city water treatment plant removes many harmful chemicals that can make you sick, they can’t catch everything. Home filtration systems offer an additional layer of water purification by removing a wide range of contaminants, including pesticides, organic compounds, chemicals, pharmaceuticals, and harmful heavy metals such as lead, mercury, and microorganisms. Keep in mind that not all water filters will remove every type of impurity. When shopping for a water filter, pay attention to the kinds of contaminants it can and cannot remove.
Water filters are rated as to the number of gallons of water per minute they can filter. If you’ve ever waited for a gravity pitcher water filter to purify water, it can take a frustratingly long time to filter even enough water for a single glass. While this slow process may be OK for a pitcher of drinking water, it won’t work for water filters designed for kitchen faucets or the entire home. Whole-home water filters, on the other hand, must be capable of filtering many gallons of water per minute, since most showers and dishwashers can guzzle up to 5 gallons of water per minute.
Installation and Maintenance
Water filter installation and maintenance range in complexity. A faucet filter involves unscrewing the aerator and attaching a hose, while a reverse osmosis system may require a more involved process. Virtually all water filtration systems can be installed by a DIYer with only basic plumbing knowledge. Maintaining a water filter typically involves the periodic replacement of filters as they wear out, and most systems make changing out the filters a relatively simple task. Cost varies depending on the complexity of the system. Multistage reverse osmosis systems with seven filtration stages may produce some of the purest water you can drink, but the cost of replacing seven different filters can quickly add up.
Our Top Picks
The water filters detailed here remove many different kinds of contaminants from your water and feature high capacities, limiting the cost of replacement. These filtration systems come from some of the best-known names in water purification.
Simple, affordable, and with a large drinking water capacity: It may be hard to beat this time-honored water filter from one of the most well-regarded names in in-home water filtration systems. It features a large water dispenser that holds 18 cups, or 144 ounces, of water, and its filter removes chlorine, mercury, copper, zinc, and cadmium. It’s compatible with Brita’s Longlast and Standard water filters, which have a life span of 120 gallons and 40 gallons, respectively. That translates to six months or two months, depending on usage.
At 10 inches tall and less than 5 inches wide, this Brita’s small size means it can fit on a countertop or in the fridge without taking up too much space. An easy-to-use tap makes filling a drinking glass or coffee carafe easy.
ZeroWater’s 10 Cup Water Filter Filter Pitcher is relatively affordable. This gravity filter features a five-stage system that uses both carbon and ion exchange technology to remove heavy metals, such as chromium and lead, pesticides, herbicides, and chlorine, as well as 99.6 percent of dissolved solids.
Its water-quality meter allows users to check the cleanliness of their water. The meter attaches to the top of the pitcher for easy access. This model has a 10-cup capacity and includes rubberized grip and one filter.
If you’re looking to filter every drop of water that enters your home, then consider this system from iSpring. It features three filtration stages, including a filter that removes sediment and two carbon filters that eliminate odors and taste while filtering out pesticides, herbicides, and other chemicals. This model doesn’t remove dissolved solids, making it a suitable option for homes on city water.
It will treat 100,000 gallons of water before the filters need replacement, which is about enough to handle the water quality needs of a family of four for up to a year. With a maximum flow rate of 15 gallons per minute, it can handle most homes’ needs. Installation is easy with iSpring’s instruction manual and online video instructions.
With its high capacity and ability to remove different types of contaminants, this model is an excellent filter to have under your sink. It boasts an impressive 8,000 gallons of capacity, which is about enough to cover a full year of water use for a family of four. It uses a five-stage filtration system that removes chlorine, heavy metals such as lead, mercury, arsenic, fluoride, and a bevy of chemical contaminants such as herbicides and pesticides. It will also filter out faucet-clogging sediment.
Push-connect fitting makes installation quick and easy. A fast flow rate produces 2 gallons per minute at 60 psi (pounds per square inch), so you won’t notice any decrease in water pressure. At just 12 inches long and 3.6 inches in diameter, this filter fits under your sink without hogging space.
If you’ve ever wondered what exactly is in those cylindrical-shaped water filters that purify water, wonder no more with this countertop model from Apex. This filter features a translucent case, allowing you to see the water flowing through each treatment stage before streaming out of the faucet and into your glass. This alkaline system removes a variety of contaminants, including chlorine, sediment, mercury, pesticides, and herbicides.
This model sits on your countertop alongside your kitchen faucet. At 16 inches high and 6 inches in diameter, this filter won’t crowd your counter. To install, simply remove the aerator for your faucet and attach the line for the filter. This system will treat up to 750 gallons of drinking water before needing a replacement filter.
FAQs About Water Filters
If you’re still wondering about what water filters can and can’t do, then look below for answers to some of the most commonly asked questions about these devices.
Q. Do water filters remove bacteria?
Only reverse osmosis water filters will remove bacteria. Chlorination and ultraviolet light will disinfect water by killing bacteria.
Q. Do any water filters remove viruses?
Water filters are not effective means of removing viruses; however, some water treatment systems can disinfect by killing viruses. The good news is that through chlorination, most water treatment plants are very effective at killing off all bacteria and viruses in the water before it ever reaches your home. Your home system can then remove the chlorine from the system.
Q. Which filter removes the most contaminants?
Reverse osmosis systems are the most effective filters for drinking water. Many of them feature seven or more filtration stages along with the osmosis process that makes them effective at moving 99 percent of contaminants from water, including chemicals such as chlorine, heavy metals, pesticides, and herbicides. Some reverse osmosis systems even add healthy minerals and nutrients to the water.