Injuries to your aquarium fish can occur several ways. They may fight with other fish in the tank, idle against the aquarium's heater, suffer from bacterial or fungal infections, or even tear their scales or fins on the tank's decor or plants. Healing an injured fish requires the use of a quarantine tank to keep the animal isolated from its tank-mates and a regiment of medications, such as Melafix. The quarantine tank should be significantly smaller than the main tank (no more than 20 gallons for small-to-medium-sized fish) with no decor and the same water parameters.
Fill the quarantine tank with water and add the proper dosage of dechlorinator, which removes harmful chemicals like chlorine. The correct dosage will be on the packaging.
Install the aquarium heater and aquarium filter. The heater typically attaches to the interior wall of the tank with suction cups while the filter hangs on the back. Consult each products' manual for specific instructions. Power on the filter and let it cycle for 24 hours, and set the heater temperature to the same temperature as the main tank.
Transfer the injured fish into the quarantine tank with a nylon net. Keep its exposure to air at a minimum. Feed the injured fish normally during its time in the quarantine tank.
Add the proper dosage of medication to the quarantine tank. The proper dosage will be on the packaging and medications vary according to the type of injury. Melafix treats abrasions and other ailments, while other medications will treat fungal infections. Consult an aquarium disease guide for help identifying specific problems.
Mix a cup of saltwater and add it to the tank. Never add salt directly to the tank, as this will burn the fish's gills. The aquarium salt will help alleviate any bacterial infections. Freshwater bacteria cannot tolerate saltwater.
Increase the temperature by 1 degree Fahrenheit per day for a week to treat many bacterial infections. Aquarium bacteria may be very temperature-sensitive and perish in warmer water.
Keep the fish quarantined for at least 10 days after it has completely healed before transferring it back into the main tank. If the problem reappears, then you may need to remove an overly aggressive tank-mate or treat your main tank with medication.