"Ick" or more commonly known as White Spots

This is one of the most common diseases that plague many fresh water aquarist, especially during fall or the raining season in the tropics where there can be a sudden temperature change which can trigger the infection under poor water conditions.

Fishes play host to some parasites/bacteria which seldom cause much harm under normal water conditions. However, the situation changes when the fish is under stress and the immune system wears down. This coupled with poor water conditions (e.g. presence of ammonia, pH or temperature variation) will exposed the fish to infection. Injuries, bites or cuts on the fish can also lead to infection if not treated properly. In the worst case scenario, the infection from a single fish can spread to all other tank mates and can lead to mortality.(This is precisely what happened in my case )

Firstly, the prevention of fish diseases must be dealt with. It's best to take the following basic precautions as first step in keeping a healthy aquarium :-

1. Avoid purchasing/adding fishes to the established tank which exhibits the following symptoms:

a) Unusual swimming behaviour e.g. tailspin, rapid or jerky movement
b) Signs of injuries to fins and body. e.g. bleeding, ulcers, skin or fin tear
c) Not eating. A healthy fish will devour any food gladly
d) Blurry eyes. Popeye or cloudiness.

2. Pay attention to the fishes for at least a few minutes a day and observe the behaviour. Stressed fishes may exhibit certain unusual behaviour :

a) Not eating.
b) Always hiding, being bullied by other tank mates regularly.
c) Coming up to the surface to breath regularly, could be a sign of an over-crowded tank or insufficient dissolved oxygen in the water (in the latter, changing fresh water will help) .

3. Ensure the water condition is kept to the ideal level.

Check for presence of ammonia and variation in pH (test kits are easily available) at least once a month. Practice regular fresh water changing, make sure the temperature and pH level is similar and not more than 50% of the water must be changed at one time. Avoid cleaning the biological filter all at once, alternate the cleaning.


If the above guidelines can be adhered, the risk of a mass tank infection can be reduced and hopefully would not have to resort to any treatment or tank "overhaul". The steps mentioned above are not hard and fast rules that one must adhere to religiously. In time, an experienced aquarist will know what to look out for before any disease outbreak.

And now, some basic in treating "white spot" disease.

Sc. name : Ichthyophthirius multifiliis (causative agent)
Distribution : World wide, in fresh and brackish water
Prevalent in water conditions : Increased Ammonia and Nitrate levels, abrupt changes in temperature especially a fall in temperature can cause an outbreak.
Infection Symptoms : Non-feeding, hiding abnormally, itchiness with rubbing & scratching , surface breathing and rapid respiration. Most obvious are the presence of white spots (about 1mm) all over the body and fins.
Treatment : The treatment prescribed varies depending on the mass of the fish, the fish general tolerance towards temperature changes and depending on the stages of the infection. The most general medication used is Malachite Green (available commonly) and the dosage is normally about 0.1mg/Litre of water. It's best to separate the infected fishes in another empty tank with similar water pH and temperature when applying the medication. Change the water every 10-12 hours and repeat the medication gradually for up to 3 days.

Note: Some scaleless and smaller fishes may not be able to tolerate similar dosage for larger fishes, it's best to reduce the dosage to half (read the medication instruction carefully, the dosage recommended may vary). If the fish can tolerate higher temperature conditions, one can also try to increase the temperature of the tank (must be done gradually) up to 27-28 degrees celcius. This will help to "kill" the causative agent which are very sensitive to higher temperature especially in the later stages of the infection cycle. The higher temperature condition should be maintained for at least 2-3 days.

Adapted from http://www.seremban.net/fishcorner/ft250399.htm.