Do you really need a water filter?

About 40% of U.S. homes filter their water, and with all sorts of toxins lurking in reservoirs and wells, perhaps yours should be among them. But filters can range from simple pitchers to whole-house reverse osmosis systems—and from a few tens of dollars to thousands. Here’s what you need to know before you buy.

If you were forwarded this and want to sign up to receive it daily, click here. Today's newsletter was written by Jeffrey Kluger and edited by Angela Haupt.