The Treatment of Ick in Fish

Diagnosis

• Ich appears as white spots about the size of a grain of salt on the fins and body of a fish. They will start out as one or two, then spread. In the final stages, there are so many spots that the fish looks like it is coated. Infected fish often will rub themselves against plants or decorations. You may also see rapid breathing.

Treatment

• Since ich is such a common disease, most aquarium stores carry a variety of medications to treat it. These are usually solutions of malachite green, formalin or copper. Treatments in tablet form have also been developed. Deciding which is best for your tank involves considering the types of fish or other animals you have, whether you have plants in your tank, and your tank's water conditions.

  If only one fish is infected, move it to a separate hospital tank and medicate it there. Continue to watch the fish in your main tank for any signs of disease. If high numbers of your fish are affected, treat the entire tank. Remove any activated carbon in your filtration system as carbon will absorb the medication out of the water. Add the medication to the tank, typically over the course of three to five days. Increase aeration, as this helps distribute the medication throughout the tank. Expect the medication to discolor your tank water for a few days. After treatment, do a 30 to 50 percent water change.

  It is very important to continue the medication for the recommended time frame, because it can only kill the parasites during one stage of their growth--while they are seeking a host or newly attached to one. You must treat the tank for a number of days to target the correct part of the life cycle. Ich infestations can also be treated by increasing the water temperature and increasing the salt content of the water for about one week. Left untreated, ich can kill fish within days and outbreaks can wipe out entire tanks.

Prevention

• The ich parasite can lie dormant on fish or within a tank until fish are weakened and unable to resist infection. Often a decline in water conditions or an increase in stress will bring about these conditions. Ich outbreaks often happen when new fish are introduced; the new fish could have brought along the infection from another aquarium, or your pets may have been stressed by the changes, allowing the ich parasite to take hold.

  Avoid these circumstances by maintaining good water quality and avoiding overcrowding and quarantining all new fish in a separate tank for up to two weeks before introducing them to the rest of your fish population. This ensures that new fish are healthy, and lets you treat any diseases that show up before they are spread to the rest of your pets.