How to Treat Aquarium Fish for Ick

"Ick" is a nickname for Ichthyophthirius multifiliis, a common parasite of freshwater aquarium fish. Also known as white spot disease, infestations are simple to recognize because infected fish have white spots about the size of a grain of salt on their bodies and gills. The parasite goes through a life cycle where it feeds on the skin of the fish (leaving the characteristic white spots), detaches from the fish, then "hatches" new microscopic parasites that move freely through the tank to infect more fish. Because of this life cycle, tanks must be treated for several days.

Things You'll Need

  • Aquarium heater
  • Air stones
  • Aquarium salt
  • Chemical treatments
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Instructions

    • 1

      Raise the water temperature to 89 degrees Fahrenheit, 1 or 2 degrees every few hours until the proper temperature is reached. Add air stones to the water to increase the aeration; warmer water holds less oxygen than colder water.

    • 2

      Watch the fish carefully for signs of stress during the heat treatment. If they appear to tolerate it, hold the water temperature at the higher level for at least 10 days. The parasite cannot tolerate high temperatures.

    • 3

      Add aquarium salt to the tank. This treatment can be done in combination with the heat treatment. Dissolve one teaspoon of aquarium salt per gallon of tank capacity in a separate container holding a sample of tank water, then pour the water slowly into the aquarium.

    • 4

      Change water frequently. A water change of 25 percent daily will cut down on the number of free-swimming parasites. Add new salt to the tank if needed because of the water changes.

    • 5

      Several brand name medications sold in pet stores can kill the parasite if the fish seem stressed by the heat and salt treatments or the infestation is severe. These treatments include chemicals like malachite green or formaldehyde in water, also known as formalin. The chemical treatments, while effective against the parasite, may also kill live plants or snails in the aquarium.