The Watersafe All-In-One Drinking Water Test kit lets you easily and cheaply test your water for several common contaminants or conditions: bacteria, lead, two pesticides (atrazine and simazine), nitrate and nitrite, total chlorine, pH, and total hardness. We bought 14 of the kits online and from three different stores (we paid an average of about $18), then bought or prepared water samples with certified levels of the relevant contaminants, from completely clean through slightly contaminated to nasty. Then we put the kits to work.

Test results. The kits demonstrated an impressive ability to detect very low levels of most contaminants in 10 minutes or less, and all provided correct readings for hardness. Water tested for bacteria is supposed to turn purple (indicating clean water) or yellow (bacteria). Ten kits worked well, but two gave no result for clean water, and two others gave no result for dirty. It’s not clear why the bacteria test in these four kits, bought at the same store, didn’t work, since the kits were right about the other contaminants.

Directions are easy to follow. One hitch: You must wait 48 hours before reading the bacteria test results, and you don’t find that out until you open the package. Government standards for the contaminants are included. If you find levels above those standards, you’re to call the Environmental Protection Agency’s Safe Drinking Water Hotline, at 800-426-4791.

CR’s take. The kit can be useful. It won’t check for every contaminant, but few other home kits cover as many. Sending water to a lab for these tests could cost at least $100.