Ich disease, or as it is sometimes incorrectly called, Ick disease, is caused by a protozoan parasite. The parasite penetrates the skin surface of the goldfish and feeds on its tissue and blood.
The irritation of the embedded parasite causes the epidermal (skin) cells to proliferate and form the characteristic small pinhead size white spots that form on the fins and body. They are more easily seen on dark colored fish but are obvious when they start appearing on fins of lighter fish.
Ich is normally considered a tropical fish disease but is also found in the cooler water that goldfish inhabit.
An outbreak of the disease is frequently caused by a sudden drop in water temperature.
A more common cause is its introduction into the aquarium from a new arrival that hasn’t been quarantined.
Ich disease has four stages:
There is some debate when the division of the cyst occurs, after the adult parasite leaves the host fish, or while still embedded in the host. For treatment purposes it doesn't matter as the methodology is the same.
The speed of this cycle depends on water temperature.
If Ich disease is allowed to progress too far, the white spots will start to cover the head and gill surfaces causing breathing difficulties that eventually leads to death.
The infected fish cannot be treated for Ich as the parasite is imbedded underneath the skin. However, the parasite can be killed once the cyst breaks releasing the juveniles into the water.
The first step in treatment is to raise the water temperature gradually into the high 80s (30oC+) using an aquarium heater. This does two things:
There are several treatments that can be used. The goldfish should already be in a mild salt bath:
My preferred method of treatment is a combination of a mild salt bath with Methylene blue or malachite green added.
I gradually increase the salt content from two to 4 heaped teaspoons per gallon. I then add the Methylene blue or malachite green.
When all cysts have disappeared after a few days, change 50% of the water without adding any chemicals. Make sure the water temperatures are the same.
Turn off the aquarium heater and keep making daily water changes until all trace of the salt and chemical are gone.
As long as the fish is active and feeding well, it can be returned to its (sterilized) aquarium once the sickbay water temperature is down to normal.Home > Goldfish Diseases > Common Goldfish Diseases > Ich Disease Treatment