Special pH Indicator Paper 2.7 - 4.7 80 Test Strips For soil, water, urine, saliva, aquarium, and laboratory use. Quickly check the pH of any aqueous solution. The indicator paper has a distinct color scale from 2.7 to 4.7 for direct comparison results. If necessary use a universal pH paper to get a "ballpark" reading, then use a special pH indicator paper to get a more precise reading. 2.7 - 4.7 is an acidic range. Grow healthier plants knowing the pH level of your garden soil. Every gardener should always know the pH level of their soil. Most plants prefer a slightly acidic soil, but some grow more successfully in alkaline soil. It is easy to test, very quick and inexpensive. The kits come with paper strips that change color and a color chart that tells the pH level. Once you know your soil's pH level, you can adjust it accordingly. To test soil pH: 1. Put 1 table spoon of soil into a bowl. 2. Add just enough distilled water to make the soil the consistency of a milkshake. The amount of water needed depends on the type of soil you have. Add a little water at a time, and constantly mix it with a spoon. 3. Let the soil sit for one hour. If the soil dries out at any point during the hour, add more water. 4. Dip a pH test strip from the soil pH tester kit in the soil, and let it sit for 20 sec. Then, rinse the strip with distilled water. 5. Compare the color on the strip to the color chart included with the pH tester kit. To test the pH of water, urine, saliva, laboratory solutions, etc: 1. Dip the test strip into the liquid you are testing. 2. Immediately take out the paper and compare the color change to the color chart included to find out the acidity level of your liquid. PLEASE NOTE: a) For best accuracy, do not expose the paper set to air or sunlight. The paper should be stored in a dark dry place, not damp. b) Can not indicate the Acid or alkali solution a density lower than 0.01%.