Did you know that boiling water removes some bacteria but not contaminants like chlorine and lead? In fact, boiling water can actually elevate its lead concentration.
If your goal is to have filtered water for drinking and cooking, an under-sink water filter is probably all you need. Those certified to the NSF/ANSI 42 standard effectively remove odors and off-tastes, and filters certified to the NSF/ANSI 53 standard remove lead and other contaminants.
If your annual water-quality report shows you have a wide range of contaminants or bacteria in your water, a reverse osmosis water filter is your best bet. These filters force water through a semi-permeable membrane to wall off synthetic chemicals like PFAS (Polyfluoroalkyl substances or “forever chemicals”) which have been linked to cancer, high cholesterol and learning delays in children.
Whole-house water filters (different from softener systems for hard water) are best for removing large sediment, such as sand and iron. (The latter can stain sinks and clothing.) These water filters can also improve the taste of your water, but the most basic ones don’t filter for the contaminants that under-sink water filters do.
"Some advanced whole-house purification systems can remove potential hazards such as volatile organic compounds [VOCs], pesticides, and heavy metals, but they’re expensive—and can be overkill," says John Galeotafiore, associate director of product testing at CR. For example, you probably don’t need filtered toilet water.
If you’re worried about sediment as well as contaminants, Galeotafiore recommends pairing a basic, less expensive whole-house water filter with an NSF/ANSI-certified point-of-use water filter for the water you ingest.
