The term “water filter” can be a bit misleading, because there are drastically different types of equipment for filtering water that share the same name. Pitchers and faucet mounts filter tap water for drinking, while whole-house water filters reduce contaminants like sediment and rust in your plumbing. The type of water filter that you need depends on the type of contaminants in your water and how much water you want to purify. Whether you plan to filter pitcher-by-pitcher or every drop that comes into your home, Pronto’s Water Filter Buying Guide will help you find the filter system that’s right for you.
Test your water before you purchase a water filter. The contaminants in your water will determine the water filter system that’s best for you. If you have more than one of the four classes of contaminants in your water, combine the appropriate water filter systems to remove them. Look for water filters that list NSF or other laboratory certification for the contaminants you need to remove.
Pair the water filtration method to your contaminants. Activated carbon water filters remove organic substances, industrial solvents and chlorine byproducts; distillation systems for microbiological contaminants and water softeners to remove heavy metals and sediment. Ultraviolet water filters are best at removing microbiological contaminants. Reverse osmosis water filters do the best job at removing the widest spectrum of contaminants, but they are expensive to operate and greatly reduce water efficiency and flow. If you have radioactive pathogens in your water, contact the U.S. Environmental Protection Agency to learn the best way to filter them. http://www.epa.gov/ebtpages/water.html
Pitcher water filters are the best choice for households of two to three people who simply need to filter drinking water. Be sure to factor in the cost and availability of replacement filters and look for pitchers with digital indicators that tell you when to change the filter.
Choose a faucet-mount or under-sink water filter if you have a large household or wish to filter water for cooking as well as cleaning. Faucet mount water filters install easily to standard faucets, but you’ll need professional installation for under-sink water filters unless you’re a skilled plumber.
These water filters connect at the water main and filter all water entering your house. A water softener is a good choice if you have mineral-rich “hard water” that can clog and corrode plumbing or destroy laundry. Compare the life spans of whole-house water filters and try to choose a model that doesn’t force you to bring in a professional each time the filter needs changing.
The most common type of water filter, also sometimes referred to as activated charcoal, made with specially treated carbon designed to absorb contaminants. It is most effective with organic substances.
A foreign substance contained in water. Four main classes of contaminants in drinking water are microbiological contaminants, organic substances, inorganic substances and radioactive pathogens.
A water filter system that boils water and captures the resulting steam in a reservoir to be used as drinking water. This system theoretically results in the contaminants being left behind in the boiling tank, but many substances have a higher boiling point than water and are therefore carried with the steam into the drinking water reservoir.
Water with an exceptionally high mineral content, typically calcium and magnesium. These minerals cause the premature corrosion of plumbing and fixtures, give water an unpleasant taste and can damage laundry.
A filtration process in which water is forced through specific membranes that allow water molecules to pass but trap larger contaminant molecules.
A filtration method where water is exposed to UV rays that kill microbiological contaminants. This step does not affect other types of contaminants, so it is often used in conjunction with other methods of filtration.
A large, in-line tank that mixes water with treatment pellets or beads that dissolve minerals and some inorganic substances in “hard” water.
All tap water contains contaminants from the water source, pipes and household plumbing. People with allergies or compromised immune systems need a water filter for health reasons, and most people feel better (and prefer the taste) when they drink filtered water.
Water filters are designed to eliminate specific contaminants, so the contaminants in your water supply will dictate the water filter that’s best for you. Your local water supplier is required to publish an annual report that lists water contaminants, but this doesn’t include additional contaminants that come from household plumbing. Test your water with a contaminant kit from a local hardware store to determine the water filter you need.
Water filters don’t require certification, but better water filters will have certification from the National Sanitation Foundation (NSF) or other independent testing labs for the contaminants you need to remove. If you see a water filter that isn’t certified, move on; you’ll find plenty of water filters that are.
There are four classes of contaminants contained in water: microbiological, organic substances, inorganic substances and radioactive pathogens. Each type of contaminant requires a specific type of water filter.
Microbiological contaminants include bacteria, protozoa and viruses. It takes a distillation system, UV disinfection or reverse osmosis system to effectively remove these contaminants.
Organic substances include pesticides, herbicides and chlorine byproducts. Most of these are easily removed with an activated-carbon water filter or a distillation system.
Inorganic substances include arsenic, fluoride and lead, as well as any man-made substances that do not contain carbon. Reverse osmosis does the best job at getting rid of these contaminants, but these water filters can waste up to five gallons of water to produce one gallon of purified water. They also remove good minerals, like iron, and are among the most expensive water filters, with some under-sink models costing more than a $1,000. For people with compromised immune systems or areas prone to heavy metal contamination, reverse osmosis is the best choice. Water softeners and distillation systems will remove some inorganic compounds as well.
Radioactive pathogens are rare, occurring naturally in some soils or resulting from the mining, disposal or storage of radioactive materials. If your water test turns up high levels of radioactive material, contact the U.S. Environmental Protection Agency immediately for detailed information on filtering and removal. The type of water filter that’s best depends on the specific type of radioactive material in your water, as all water filters have varying degrees of success with these contaminants.
If you have multiple types of contaminants in your water, you will need a combination water filter or several filters to keep your water clean. Combining a plumbing-based water filter with faucet and pitcher filters is the most cost-effective solution.
Pitcher water filters are best for households with two or three people who only need to purify a moderate amount of drinking water. Most pitcher water filters use an activated carbon filter to remove organic chemicals, industrial solvents and chlorine byproducts—the contaminants that give water an unpleasant taste.
Look for pitcher water filters from well-known brands to ensure that replacement filters will be readily available, and include the cost of replacement filters when comparing models. Choose a pitcher water filter with a digital indicator that alerts you when it’s time to change the filter.
If your water supply contains large amounts of organic contaminants, you have what is known as “hard water,” or water that is rich in minerals. Hard water takes a toll on laundry and household plumbing, and you should consider installing a water softener, which filters water through a series of replaceable beads to capture excess minerals.
Faucet-mount and under-sink water filters are good choices for medium to large households that need more filtered water than a pitcher-style water filter can provide, or any household that wants to filter water for cooking and coffee as well as drinking. Faucet-mount and under-sink water filters offer more water filtration options, including reverse osmosis and ultraviolet disinfection, along with basic activated carbon filters.
Most faucet-mounted water filters simply screw on to a standard faucet fitting. If you choose an under-sink water filter, include the cost of installation unless you know you know your way around your home’s plumbing system. Improperly installed water filters may leak or provide incomplete filtration.
Under-sink water filters range in price from $50 to more than $1,000 depending upon the filtration method used. As with any water filter, be sure replacement filters are readily available and that it’s clear when you’ll need to change the filter. Look for water filters in this category that feature an on/off switch so you can switch to unfiltered water if you need more water pressure.
Whole-house water filters connect at the water main and filter all the water that enters your house. These are expensive to install and should only be used if you need to filter hard water or have a high level of contaminants. All filtration methods can be installed at the main, but some water filters will restrict flow to the point that water pressure drops to unusable levels. It’s best to choose a whole-house system that filters out one or two key contaminants and to use a combination of pitchers or sink water filters for others.
The filters in whole-house systems typically last about 6 months, which is longer than faucet-mount or under-sink water filters. Compare filter life spans when shopping, and try to find a system that lets you change the water filter yourself without incurring the cost of a professional.