Organism: Ichthyophthirius multifilis
Names: Ich, White Spot
Description: Ichthyophthirius multifilis, ich for short, is a parasitic organism that feeds on the blood and epithelial cells of its host. Although the disease is the equivalent of a skin infection, it can easily be fatal to a fish stressed by poor diet, water conditions or aggression.
Symptoms:
1. Small white spots resembling sand or salt.
2. Fish is flashing (rubbing against rocks, gravel or tank).
Infected fish are covered to various degrees with small white spots. Severe infestations are easy to spot, but small occurrences often go unnoticed. However, Ich won't remain unnoticed for long. Like a bad penny, it will be back with a vengeance if not treated properly. The adult parasite burrows into the skin of its victim, feeding on blood and dead epithelial cells. The irritation caused by the burrowing parasite causes the skin of the fish to swell and produce white cysts seen as a small spots. It's not unusual to see infected fish flashing against rocks and gravel in an effort to get relief.
After several days of feasting, the engorged parasite develops into a trophozoite, burrows out of the fish and sinks bottom of the tank. Secreting a soft jellylike substance, it forms a protective membrane inside of which it divides into hundreds of baby parasites, known as tomites. The hungry tomites soon leave their home in search of a fresh fish to dine upon.
It is during the free-swimming stage that the parasite is vulnerable to treatment. Once it has burrowed into a new host fish it is safely protected from chemicals in the water.
Treatment:
1. Raise water temperature to between 82 and 85 degrees F
2. Increase aeration and surface movement. This will help with oxygenation and gas exchange.
3. Salt for 10-14 days. 1 Heaping tablespoon per 5 gallons of water
4. Perform water changes between treatments
The entire cycle can take up to 2 weeks. I like to go a little longer just to make sure that the infestation has been dealt with. Higher temps shorten the cycle between adult and free swimming tomites. Therefore, raising the water temp shortens the time it takes for the parasite to reach the stage in which it is susceptible to medication/salt.
When raising the temp of the water do so slowly. Raising the temps to quickly can easily shock your fish and kill them. It can also starve them of oxygen so have your aerator ready.
Treatments must be given for a long enough period to assure that all parasites are gone. Watch carefully for other infections, as secondary infections often occur where the skin has been damaged by the parasite. The salt will also help with this, as it is a natural healer. Although nothing kills the parasite once it has checked into it's fish "hotel", several chemicals kill ich once it has left the fish. Malachite green, methylene blue, quinine hydrochloride, and mepracrine hydrochloride are all effective, and are available under several brand names. Be careful though as all of these chemicals can be hazardous to you and your fish. Especially scaleless fish like plecos and catfish. This is one of the main reasons I don’t like to medicate. Salt is just as good as any of those meds and is far less harmful to you and your fish.
Regardless of the treatment used, it should be given continuously for 10-14 days to ensure all parasites are killed. Between treatments a partial water change is recommended. Keep water temperatures higher than usual to speed up the life cycle of the parasite. Discontinue carbon filtration during treatment if you are using one of the medications, as it will remove the chemicals. There is no need to pull carbon if you are using salt. Personally I don’t use carbon unless I am trying to remove chemicals or smells from the water.
Prevention of Ich:
1.Quarantine new fish for two weeks in a separate tank.
2. Treat plants before adding to tank.
3. Keep your Ammonia, Nitrites, and Nitrates under control.
4. Provide fish with a nutritionally balanced diet
The best way to avoid Ich is to quarantine all new fish in a separate tank for two weeks before moving them to the regular tank. When quarantine is not possible, a prophylactic treatment may be used. Either methylene blue or malachite green given when new fish are introduced and again four days later will help reduce incidence of infection. New plants should also be treated, as they can carry ich cysts. Maintaining high water quality, avoiding temperature fluctuations, and providing a robust diet is the best preventative for ich and other diseases. Remember stress is a major cause of ich, as the fish’s natural defenses to the parasite and other diseases have been compromised when they are stressed.
This is by no means the end all be all to getting rid of ich but it has helped me keep my tanks ich free for a long time.
Keeper
Subject: Ich and how to deal with it. 
