Clears Ick fast Fast, Safe, Effective Protects against secondary infections No need to raise water temperature Tetra Fizz Tabs are fast dissolving premeasured tablets that make caring for you aquarium faster, easier, and more convenient. Tetra Ick Guard is a soothing conditioner that quickly clears ick (Ichthyophthirius multifiliis), or white spot, on freshwater fish. Ick is usually the result of sudden changes in the aquarium water temperature or stress. Left untreated, ick spreads rapidly and is usually fatal. Special ingredients have been added to protect fish from secondary infections.