Pool Water TestingThis Tester Is Designed To Test Ph And Chlorine Level For Swimming Pools And Spas. No Other Chemicals Are Needed. Read The Instructions Carefully, You Will Quickly Master Its Use. Different Test Situations Have Different Rules. Precise ReadingA Large Screen For Quick And Accurate Display Of Ph And Chlorine Levels, You Can Easily Know The Result. High Quality The Case Is Made Of Selected Plastic, Which Is Durable. The Tester Is Compact, Lightweight And Easy To Carry. With A Hole For Convenient Hanging. AttentionPlease Do Not Immerse The Probe In Liquid Other Than Pool Or Spa Water. Please Turn The Switch To The Off Position When Not In Use. Please Store The Tester In A Cool, Dry Place. UsageBefore Using This Tester For The First Time, You Need To Adjust It To Your Pool Or Spa Water In The Following Sequence: 1.Test Your Pool Or Spa Water Using A Test Kit. Conventional Liquid Test 2. Record Level Of Chlorine Salt Reading On Your Needs.3. No Adjustment Is Required For Ph.