Choosing Home Water Filters & Other Water Treatment Systems
Step 1: Know your water source
Your water filtering needs depend on the quality of your particular water supply, your personal preferences when it comes to taste and odor, and any special health circumstances in your household. To choose the best filter for your home water consumption needs, it is helpful first to learn more about your water source. Understanding what contaminants may already exist in your water is an important first step when deciding whether you want or need a filtration system and, if so, what type will best meet your needs.
Do you get your water from a private well or cistern?
If you get your water from a private well, you should have your water tested by a state-certified labexternal icon at least once a year. Before you hire someone to test your water, make sure they are certified, and make sure they will test for total coliform bacteria, nitrates, total dissolved solids, and pH levels, and other contaminants common in your area. Contact your local health department for information on contaminants in your area and for suggestions on water tests you should request. You should also get your water tested if someone in your household becomes pregnant or if a child joins your household 1. Also consider testing your water if you notice changes in color, taste, or odor. Regular testing at a certified lab can provide you with information on levels of different contaminants in your water. Once you know whether any contaminants found in your water exceed the recommended levelsexternal icon, you can take steps to choose a filter that will reduce those contaminants.
If you collect and use rainwater, visit the Rainwater Collection page for information on possible contaminants and preventing illness.
Do you get your water from a public system?
If so, you will get a report on your water each year. EPA requires all public water systems to send an annual report about the quality of drinking water, as well as contaminant levels, to people whose water comes from public sources. This report, called a Consumer Confidence Report (CCR), is sent by July 1 of every calendar year and will come in your water bill.
- Committee on Environmental Health and Committee on Infectious Diseases. Drinking water from private wells and risks to children.external icon Pediatrics. 2009;123(6):1599-1605.
Step 2: Think about why you’re considering a filter.
These are some common reasons that people choose to use water filters. Knowing what you need or want from your water treatment system is an important first step to choosing the right system for you.
You might be surprised to learn that the main function of popular refrigerator and pitcher filters is to improve the taste of your water, and most don’t fully protect against germs and many other contaminants.
Some people do not like the taste of their tap water. Sometimes this is because of the disinfectant (like chlorine) that helps keep the water safe from germs. Sometimes minerals or other naturally occurring contaminants like sulfur-containing compounds that are not harmful change the taste of the water. Activated carbon filters (the type of filter found in many refrigerators and pitcher filters) can help reduce unpleasant tastes and odors. Reverse osmosis systems can also improve taste and also reduce the levels of common chemicals such as lead. Check the label to ensure that taste and odor (NSF 42) are addressed by the particular filter you are considering. Keep in mind that if you use a chlorine-removing whole-house filter, you might end up increasing the amount of germs that grow in your plumbing.
Most harmful contaminants can’t be seen, smelled, or tasted. Some harmful contaminants, like volatile organic compounds (VOCs) that sometimes contaminate private wells, can give water a bad taste and might smell like gasoline or other chemicals. There are many different kinds of VOCs, and they have different health effects: Some cause cancer, irritate skin, affect mucous membranes, or damage the nervous system, liver, or kidneys. To identify the best filter, special testing may be needed to determine which VOCs are present in your water. It is best to use a point-of-entry filter system (where your water pipe enters your house), or whole-house filter system, for VOCs because they provide safe water for bathing and cleaning, as well as for cooking and drinking. Activated carbon filters can remove some VOCs.
If you have a private well and notice a change in the taste of your water, consider having your well water tested. If you have a public water system and notice a change in the taste of your water, report this to your water company. Just keep in mind that the taste and smell (or lack thereof) of water is not necessarily an indication of how free it is from germs and chemicals.
Step 3: Consider how the filter fits your home, lifestyle, and budget.
Many different types of filters are available to consumers. 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. No filter eliminates all contaminants, so understanding what filters do and do not do is important.
What does the filter remove?
Read the label to see if it is NSF-certified. If it is, you can search NSF’s databaseexternal icon to learn more about what a particular model is certified to protect you against. Labels on water filters also typically state the contaminants that are reduced, which can help to guide your choice. Be sure to read labels carefully yourself and verify the manufacturer’s claims with an independent source, as not all sales representatives will be familiar with your needs.
Keep in mind that most brands include many different types of filters. Sales people might be able to help you make an appropriate selection, but remember that they are sometimes paid to sell a particular brand. You should check claims and read the fine print on filter packaging for yourself and ensure that it will work for your purposes before purchasing.
Don’t assume that if the filter removes one contaminant, it also removes others. Filters that remove chemicals often do not effectively remove germs, and vice versa. Some water treatment devices that remove chemicals, such as reverse osmosis, ion exchange, or distillation systems, might also remove fluoride. Children who drink water with levels of fluoride <0.6 ppm might need a fluoride supplement. Check with your child’s pediatrician or dentist for specific recommendations.
How much does the system cost?
The prices of different filtration systems can vary widely, from simple systems that can cost under $20 to complex systems costing hundreds of dollars and requiring professional installation. In addition to the price of purchasing and installing the system, consider the cost, schedule, and ease of maintenance, such as changing filter cartridges. In order to continue to work properly, all water treatment systems require maintenance.
How much filtered water do you need?
Some filters are slow, while others can filter large amounts of water quickly. If you only need the filter for personal drinking water, you may not need a fast filter.
What kind of system do you need, and how does it fit into your home?
Filters commonly found in homes and stores include water filter pitchers, end-of-tap or faucet-mounted filters, faucet-integrated (built-in) filters, on-counter filters, under-sink filters, and whole-house treatment units. No filters or treatment systems are 100% effective in removing all contaminants from water, and you need to know what you want your filter to do before you go shopping (see Step 1). Not all filters of a particular type use the same technology, so you should read the label carefully.
Step 4: Maintain your filters.
Filters that are not well maintained can do more harm than good, so it is crucial to follow all manufacturers’ instructions for proper maintenance. Change filters regularly to keep your drinking water healthy. Water softeners need to be regenerated (flushed) on a regular schedule.
People with compromised immune systems
Filters collect germs from water, so someone who is not immunocompromised should change the filter cartridges. Anyone changing the cartridges should wear gloves and wash hands afterward.