Ich is a very common ailment found among tropical fish. It is not a disease, but rather a parasite that attaches its self to the body of a fish and eats the fluid and tissue. In the ocean where the density of fish is low, these parasites aren’t a problem because they can’t find a host very easily. In a home aquarium where the density of fish is much higher one parasite can destroy an entire tank.

Symptoms – The most common symptom is small white spots on the fish, other signs include slimy skin, frequent rubbing against other objects, slow and heavy breathing and loss of appetite.

Treatment – Ich parasites have three different stages in their life cycle, the trophozoite, trophant, and tomite. In only the tomite stage are they vulnerable to treatment. These parasites also react to different water temperatures. At 85 degrees F they will not attach onto a fish, will not reproduce at 86 deg. F and die at 89.5 deg. F. Most fish cannot tolerate 89.5 deg. F temperatures but raising the temperature to 86 degrees for 10 days will most likely cure the problem since that is the life cycle of the parasite. Slowly raise the temperature 2 degrees F every hour until you’ve reached 86 deg. F or if your fish can tolerate higher, go to 89.5 deg. F for 3 or 4 days to kill the ich. If you raise the temperature to 89.5 deg. F lower it to 86 deg. F for the next 6 or 7 days.

If you increase the temperature keep in mind that warm water increases metabolism creating a need for more oxygen, but warm water has lower levels of oxygen. Add oxygen to your fish tank by lowering the water level, you may need to add an airstone as well.

Ich can also be treated with medications found at your local pet store. These medications are generally effective, but some of them are only for freshwater aquariums or may not be safe for your kind of fish. Read the instructions carefully before purchasing or using any ich medication.

Preventing ich is a simple as quarantining new fish for at least two weeks before adding them to the main aquarium. Most cases of ich are caused by a new fish being infected with the parasite and spreading it to the rest of the fish.