The Pentair Aquatics Lifegard 6 Way Test Strips are dipped in the aquarium water and and the resulting test strip color will show whether six critical levels are normal or at critical levels. Tests for alkalinity, pH, nitrite, nitrate, hardness and ammonia. Can be used for saltwater and freshwater tanks, and for ponds.New technology (patent pending)Dip & read one-step testNo separate vial requiredLeak proof pop top lidDesiccant liner for maximum moisture protection25 tests