Tetra Ick Guard fizz tabs are fast-dissolving, premeasured tablets that make caring for your aquarium faster, easier and more convenient. This easy-to-use, soothing conditioner quickly clears ick (Ichthyophthirius multifiliis), or white spot, on freshwater fish. Usually the result of sudden changes in water temperature or stress, ick can spread rapidly if left untreated and is usually fatal. This fast, safe and effective remedy clears ick and helps protect fish against secondary infections.