Test strips are fast and inexpensive, and detect contaminants by measuring the water pH, which is related to its acidity. However, they don't offer the same amount of accuracy as other drinking water testing techniques, reports the Water Testing Blog.The paper strip is dipped into the water for 10 seconds, with a gentle shaking movement. After 20 seconds, the white strip gains color, which can be analyzed according to the test manufacturer's instructions. According to the test's manufacturer Aqua Safe, pH results for drinkable water are ideal from 7.5 to 8.5.
Color comparators are accurate but can be more expensive, especially when testing for lead, copper, iron or other advanced parameters, reports the Water Testing Blog. Color comparator kits are often used to check water quality in swimming pools and are based in color change when the water is mixed with special reagents. This technique also tests water for pH and chlorine levels, according to Insta Link.
Electronic colorimeters are convenient because they present a digital reading, which prevents human contact with chemical compounds when performing the test. They are highly accurate because they remove any human interpretation, reports the Water Testing Blog. In the guide "Water Quality," the American Water Works Association reports this testing technique as the one most often used for many substances, such as chlorine and other chemicals.