In order for fish to thrive, pond water needs to be tested. Regular testing of water pH, nitrite, nitrate, carbonate hardness and general hardness is an essential part of routine pond maintenance. Levels should be tested weekly to make sure they do not reach undesirable levels that could stress fish which can lead to illness and death. Pond Care 5-in-1 Pond Test Strips use highly accurate color charts for precise and easy to read test results. And the stay dry tube with desiccant liner offers protection against humidity to ensure efficacy of all test strips. You just dip and read! Contains 25 test strips.