Save: Ph test strip should be stored in a dry place to avoid light, and no sour and alkaline air can be stored again.<br>When using, please do not immerse the Ph strip in the test liquid. It can cause the test results to be displayed incorrectly.There is a detailed English description on the back of the product.<br>Test paper can not indicate the Acid or alkali solution when its density was lower than 0.01%. <br>The color changes of the test strip need to be matched within 15 seconds.