2 rolls, lightweight and compact reel design for easy use and portability. The pH test paper is made from high quality litmus paper which provides reliable results in seconds in the pH range of 0-14. Indicator strips come on a roll, just pull them to your desired size. Take a small test strip, touch it with the liquid to be tested and, after a few seconds, compare the test result with the standard color of the cardboard. pH tests are commonly used to check the acids and bases. Ideal for testing saliva, drinking water, aquariums, hydroponics, food, soil, detergents, soaps and more. Universal pH test paper is a good educational resource for schools and labs, and can also be used for testing aquariums, hydroponics, aquariums, industrial testing,