Parasite Guard Fizz Tabs removes external and internal parasites from tropical fish including flukes, internal worms, lice, anchor worms, and flagellates such as hexamita or spironucleus associated with hole-in-the-head disease. Also protects against secondary infections. Tetra Fizz Tabs are fast dissolving, premeasured tablets that make caring for your aquarium faster, easier and more convenient. Simply drop the Fizz Tabs tablet into your aquarium water, the fizzing action assures you the ingredients are working immediately! With Parasite Guard Fizz Tabs, there's no need to raise the water temperature. Safe for freshwater aquarium fish and plants. Treats up to 80 gallon aquarium.