Copper-Aid is an effective treatment for external parasites on aquarium fish. It helps cure most external parasite issues on fish that exhibit visible symptoms such as spots, extra skin mucus, scratching, rubbing, rapid breathing, loss of body color, or visible worms. This treatment does not require water changes or pH adjustments assuming levels are ideal before treatment. You can maintain all normal filtration and air flow during treatment. Simply replace the carbon after treatment completion. When doing water changes, treat the replacement water with Copper-Aid to ensure the prevention of any further external parasite issues. NOTE: Contains Chelated Copper Sulfate - Remove all invertebrates without an exoskeleton (anemones, jellyfish etc.) from aquarium prior to treatment. Copper-AID may be harmful to plants and some snails. DO NOT OVERDOSE. For ornamental pond and aquarium fish ONLY, not for human, medical, or food fish use.