Best Water Filters Based on In-Depth Reviews

Pure, clean, crystal-clear water is not a luxury but one of life’s most essential, basic needs—and a human right. Whether it’s for drinking, cooking, or cleaning, the water we use must be of the best possible quality. 

To this end, water filters are one of the best options for individuals and families due to their relative affordability, effectiveness, durability, and ease of use. The best among them are able to remove most common contaminants, improve taste, and even change the water’s texture so that it feels softer. 

To help you make an informed decision upon purchasing a filtering system, here are a few things you should know about the way water filters work. 

There are five main types of filtration systems

Not all filters are created equal. In fact, there are several filtration techniques, each capable of eliminating specific contaminants and particles. One is not better than the others—rather, the one that’s right for you will depend on your household water needs. Let’s take a brief look at the most common ones.  

Reverse Osmosis 

Good for removing: Fluoride, Hexavalent Chromium, Arsenic, Nitrates, Copper, Radium, and more.

By using pressure, reverse osmosis pushes water through a membrane with small holes so that all contaminants remain on one side and clean water comes out the other. This system is ideal for under-sink, point-of-use filters but, due to its slowness, it’s not recommended for whole-house use. You should also keep in mind that, since the system flushes all the water that is not filtered—only ⅓ of the water is purified–there’s a high amount of waste. 

Activated Carbon

Good for removing: Chlorine, Chloroform, Organic Substances, Sediment, and Magnesium

Via the process of adsorption, pollutant molecules are trapped inside a porous carbonaceous material–such as coal, coconuts, nutshells, and wood–that has been treated with oxygen. When the water passes through, the contaminant particles stick to the activated carbon so that only clean water comes through. Its most common use is to eliminate bad odors. 

U/V Disinfection

Good for removing: Bacteria and Viruses

By attaching to a particle’s DNA, the electromagnetic energy of light destroys harmful microorganisms and prevents them from reproducing. It’s one of the most environmentally safe ways to filter water. However, while it does deactivate living organisms, it does not remove particles, bad tastes, or odors.

Ion Exchange

Good for removing: Hard Water and Radioactive Material

In this system, one type of ion is physically replaced by another through the use of small resin beads. For example, for softening hard water, the resin beads exchange magnesium and calcium ions with sodium or hydrogen ions. However, because of its high sodium concentration, these filters are hardly ever used for filtering drinking water, and are mostly used as softeners. 

Distillation

Good for removing: Fluoride, Arsenic, Lead, Viruses, and Other Contaminants

One of the oldest filtering methods in the world, distillation is the process by which steam from boiled water is condensed to form purified water. When the contaminated water boils, the contaminant particles with boiling points lower than that of water do not evaporate and are left behind, leaving only clean steam which, when cooled, becomes contaminant-free water. However, contaminants with boiling points equal to or higher than that of water—benzene, for example—will evaporate along with the water, meaning that they must be removed prior to condensation.  

Point of Use vs. Point of Entry

The distinction between “point of use” and “point of entry” has nothing to do with a filter’s quality, but rather the specific water line at which the liquid is filtered. 

Point of entry systems filter the water at the main water line, so that all the water that flows from every tap in your house is already filtered. Whole-house filters are the best example of this type of filtration system. 

Point of use systems, on the other hand, are installed at specific taps, so that only the water flowing from said taps is filtered. Reverse-osmosis, under-sink water filters are the best example of this kind of system. 

Look for the NSF/ANSI and/or Water Quality Association certifications

Since the Federal Government does not regulate water filters for home use, the American National Standards Institute (ANSI)—a non-profit organization—has stepped in. According to Jana Zabinski, director of communications and public relations at ANSI, “As coordinator of the U.S. standardization system, ANSI itself does not develop standards; rather, the Institute oversees the process by which standards are developed, and accredits standards developing organizations (SDOs) that meet ANSI’s Essential Requirements”. 

ANSI works hand in hand with several health and safety organizations and laboratories—most importantly the National Science Foundation (NSF) and the Water Quality Association—to make sure that water filters meet or exceed the water quality standards set by the Environmental Protection Agency. 

The ANSI/NSF certification is only awarded to water filtering systems that, after thorough evaluation, are found to meet the design, material, and performance requirements of national standards. The certification is the most recognized and respected in the drinking water industry, and serves as a quality guarantee for consumers. For this reason, we only recommend filters certified by NSF/ANSI and/or the  Water Quality Association. 

There are two types of NSF/ANSI certifications for water filters: one for water safety and the other for water aesthetics, taste, and odor. Each is assigned a number, and here is a brief summary of what they stand for:

• NSF/ANSI 42
  For filters that reduce chlorine, taste, and odor. 

• NSF/ANSI 53
  For filters that reduce contaminants. 

• NSF/ANSI 44
  For water softeners. 

• NSF/ANSI 55
  For filters using UV light. 

• NSF/ANSI 58
  For reverse osmosis systems. 

• NSF/ANSI 62
  For distillation systems.

• NSF/ANSI 177
  For shower filters. 

• NSF/ANSI 401
  For systems that filter emerging contaminants.

• NSF P477
  For filters that reduce microcystin. 

• NSF/JWPA P72
  For filters that reduce all forms of iodine in drinking water. 

An NSF/ANSI certification does not mean that a water filter will reduce all contaminants, but only those specified by the certification. When buying a home water filter, make sure the product is certified to remove the contaminants that affect your household. 

These are the most common contaminants found in water

According to the Environmental Working Group’s (EWG) 2019 Tap Water Database, tap water across the US may have upwards of 287 contaminants, each belonging to one of four categories: physical, chemical, biological, and radiological. These are some of the most concerning since they have been linked with higher risks of developing cancer, reproductive and digestive problems, kidney malfunction, lung infections, and neurological disorders.

• Arsenic

• Hexavalent Chromium

• Aluminum

• Lead

• Ammonia

• Barium

• Uranium

• Cadmium

• Silver

• Chloramine

• Radium

• Copper

• Mercury

• Bacteria

• Viruses

• Nitrates

• Fecal Coliform

• Benzene

• Vinyl Chloride

• Pharmaceuticals