Copper is often used as a treatment for parasite infested fish and it is essential that the correct; Tap water can also be naturally high in copper and it is a canvas advisable to test for this on a R; the Salifert Test Kit offers a very sensitive and accurate test for measuring dissolved or weakly CH; Lasts for several copper cures or provides sufficient for up to 50 tests on tap or aquarium water as; CA BE USED FOR MARINE, fresh and garden pond water