Test kit contains pond testing for : Ammonia, Nitrite, Nitrate and Ph Broad range. Why Test? Ammonia, Toxic waste produced by fish.High levels kills fish. Nitrite, Toxic product of ammonia break down. Causes fish health problems. Nitrate, End product of waste breakdown. Causes stress and algae problems. PH Broad Range, Acidity or alkalinity of water. Inccorect PH will stress and kill fish. There are 20 tests in total, tests of each parameter PLEASE NOTE THESE ARE AT A REDUCED PRICE DUE TO THEM HAVING A SHORT DATE OF 11/2015