It is important to treat ich desease quickly, as they are a form of parasite which can be deadly to your fish. They remain under the skin of your fish, feeding on the cells it destroys, until it reaches maturity. It then burst free and attaches itself to another surface, such as a plant, where it multiplies in huge quantities. Many ich infestations are the result of these items being introduced to your tank, unknowingly bring ich with them.

Early signs of fish ich disease can include having your fish rubbing or scraping itself against rocks or other surfaces. In more advanced stages, your fish may become lethargic (or lazy), spending most of its time on the bottom of the tank or pond.

Koi are commonly affected by ich disease, but the white spots may be difficult to spot in their early stages, so it is recommended that a skin scrape for microscopic identification can be made.

It is important to know that ich are only vulnerable to treatment when they are emerging, not when they are under the skin, or on other surfaces waiting to "hatch". Therefore you must take in mind that treatment for ich disease will have to be accomplished over a period of time, and may need to be continued longer than treatments for other diseases or parasites. This is to prevent reinfestation.

Some treatments include prolonged salt immersion, and the use of other available treatments. Most pet supply stores and the internet are excellent sources on helping you identify the signs of ich disease in fish, and for helping you treat it.