Choosing the Best Home Water Filters: A Guide to Clean & Safe Drinking Water
We have compared and analyzed a dozen websites – from Amazon to Wirecutter – for their recommendations and ratings for home water filters and compiled the results into this guide for you.
Consumers have a choice of many different types of filters. Determining which type is most appropriate for you—or whether you need a filter at all—depends on what functions you want a filter to provide. You might want to test the quality of your water first with one of the many available water quality testing kits
. It is important to understand that no filter eliminates all contaminants
, so understanding what filters do and don’t do is important.
Based on use, the recommendations are grouped into four categories: The best water filter pitchers and countertop dispensers, the best faucet-mounted water filters, the best under-sink water filters, and the best reverse osmosis filters.
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But let’s start with the water filter basics first: why and how.
Why use a water filter – are they really necessary?
Do you need a water filter at home? Let's discuss the importance and functionality of water filtration systems.
Tap water can contain various contaminants, such as microorganisms, chemicals, and toxic substances, turning it potentially unfit for consumption. Depending on the water quality in your area, a water filter might be a necessity.
Water filters serve diverse purposes. Some enhance the taste of your water, while others efficiently eliminate harmful chemicals or bacteria. However, remember that no single filter can eradicate every kind of contaminant. Also, those with access to high-quality tap water may not need a filter.
It's important to note that tap water also carries beneficial elements, like fluoride that aids in preventing tooth decay, and controlled amounts of disinfectants like chlorine, ensuring the water is germ-free. Certain harmful substances, like lead and parasites (e.g., Giardia and Cryptosporidium), can also be present. While filters can remove both beneficial and harmful substances, depending on your individual requirements, water filtration may not always be necessary.
A reliable way to assess a water filter's functionality is to check for an NSF certification. NSF International is an independent organization that formulates public health standards for various products. You can refer to the NSF online database
to understand what each water filter protects against. The NSF standards related to water treatment include Standard 41 (taste and odor), 53 (cyst reduction), 58 (reverse osmosis), and 62 (distillation).
How do water filters work?
Want to understand how water filters function? Let's delve into the three essential types of water filtration prevalent in home water filters: mechanical, adsorption, and reverse osmosis.
Mechanical or microporous filtration physically eliminates contaminants such as sediment or dirt from the water via a barrier. The filtration efficacy is governed by the pore size of the filtration membrane — smaller pores trap more particles. For instance, a 5-micron pore can filter out most particles visible to the naked eye, while a significantly smaller 0.5-micron pore can eliminate parasites like Giardia and Cryptosporidium.
Adsorption filtration employs a process where small particles in water adhere to a larger surface (adsorbent). Historically, carbon or charcoal has been an effective adsorbent in water treatment. Modern household water filters typically use an advanced form of carbon, known as activated carbon, to trap and retain dissolved contaminants. These filters excel at eliminating chlorine, sediment, volatile organic compounds, and improving taste and odor. However, they fail to remove arsenic, heavy metals, fluoride, bacteria, or pharmaceutical compounds.
Reverse osmosis, distinct from physical and chemical filtration methods, uses pressure to propel water through a semipermeable membrane. This membrane, with pores small enough to capture contaminants yet large enough to allow water to pass, provides thorough filtration.
A multi-stage reverse osmosis water filtration system can effectively remove all the contaminants mentioned above and more. While countertop filters can purify down to one micron, reverse osmosis systems filter down to .0001 microns, removing up to 99% of all water contaminants, including arsenic, fluoride, heavy metals, and pharmaceuticals. Reverse osmosis filters offer the most comprehensive contaminant removal.
Combined with other filters such as a mechanical (sediment) filter and an absorption (activated carbon) filter, reverse osmosis provides a potent solution for purifying water, resulting in a supply with minimal contaminants.
The best water filter pitchers
Sources for further information and research
CDC. A Guide to Drinking Water Treatment Technologies for Household Use
EPA. Ground Water and Drinking Water
EPA. Home Drinking Water Filtration Fact Sheet
NSF. Consumer Tips for Choosing a Drinking Water Filter to Reduce Contaminants
NSF Certified Drinking Water Treatment Units, Water Filters
Safe Drinking Water Foundation
Frequently Asked Questions (FAQs) about Twistronics
What is a water filter?
A water filter is a device that removes impurities and contaminants from water by means of a physical barrier, chemical process, or biological method. Water filters can help improve the taste of your water and may even protect your household from harmful contaminants.
What are the types of home water filters?
The main types of water filters for home use include pitcher filters, under-sink filters, faucet-mounted filters, and reverse osmosis systems. Each type has its pros and cons and is best suited for specific needs and water quality issues.
How do pitcher water filters work?
Pitcher water filters work by pouring water into a top reservoir that drains through a filter into a pitcher below. These filters can reduce or eliminate many common contaminants, but they have limited capacity and require regular filter replacement.
What are the benefits of under-sink water filters?
Under-sink water filters are installed under your kitchen sink and filter water as it flows from your water line. They can filter larger quantities of water than pitcher filters, and they're out of sight, saving counter space. They require more complex installation but offer long-lasting filtration.
How does a faucet-mounted water filter work?
A faucet-mounted water filter attaches directly to your faucet, allowing you to filter cooking and drinking water easily. When you turn on the faucet, water is diverted through the filter before it comes out of the faucet, removing contaminants.
What is a reverse osmosis system?
A reverse osmosis system is a water purification system that uses a semipermeable membrane to remove ions, molecules, and larger particles from drinking water. It's one of the most thorough filtration methods available and can remove a wider range of contaminants than other types of filters.
How often should I change the filter on my home water filtration system?
The frequency of filter changes depends on the type of filter and the quality of your water. However, as a general rule, pitcher filters should be replaced every two months, under-sink and faucet-mounted filters every six months, and reverse osmosis filters every 2-3 years. Always follow the manufacturer's instructions for your specific filter.
How to choose the right water filter for my home?
Choosing the right water filter depends on your specific needs. Consider factors like the quality of your water, the type and amount of contaminants you want to remove, the cost of the filter and its replacement parts, and how much water you use.
Can a water filter remove lead?
Certain types of water filters can remove lead, but not all. Look for filters that are specifically certified for lead removal. Reverse osmosis systems, certain types of activated carbon filters, and some faucet and under-sink filters can be effective at removing lead.
Are water filters environmentally friendly?
Water filters can be an environmentally friendly choice compared to bottled water, as they reduce plastic waste. However, the environmental impact also depends on the type of filter and how often it needs to be replaced. Look for filters with recyclable components or buy from companies with take-back programs for used filters.
Can water filters improve the taste and odor of my water?
Yes, water filters can greatly improve the taste and odor of your water by removing chlorine and other contaminants that can affect the taste and smell of water.
What is the cost of a home water filter?
The cost of a home water filter varies greatly depending on the type of filter. Pitcher filters are generally the least expensive, while under-sink and reverse osmosis systems are more costly. However, also consider the cost of replacement filters and the lifespan of the filter when determining overall costs.
Is filtered water better than bottled water?
Filtered water can be a better choice than bottled water for a few reasons. It's often less expensive, reduces plastic waste, and you can control the quality with your choice of water filter. Moreover, some bottled water is just filtered tap water.
Can I install a water filter system myself?
Depending on the type of filter system, you might be able to install it yourself. Pitcher filters and most faucet-mounted filters are simple to set up. Under-sink and reverse osmosis systems require more complex installation and might require a professional, especially if modifications to your plumbing are necessary.
Does filtering water remove beneficial minerals?
Some types of water filters, like reverse osmosis systems, can remove beneficial minerals like calcium and magnesium. However, many filters leave these minerals intact. If you're concerned about mineral loss, look for a system designed to re-mineralize the water or consider a filter type that retains these minerals.