White Spot:
White Spot or Ich {chthyophthirius} mostly occurs when the fish become stressed either from sudden water temperature change or when moving the fish to another tank. Detection is quite easy as the affected fish will show signs of small White Spots, first on the lateral fins then slowly over the whole body. Treatment for White Spot is easily cured by increasing the temperature of the tank to 27°-28°C and adding one of the white spot cures like Wardley White Spot Cure available from most aquarium shops. If the affected fish is in a community aquarium you could try to catch it and place it in a quarantine aquarium, but normally if one fish is affected then there is a strong likelihood that all the fish could catch it. So it is advisable to treat the whole aquarium.

Ulcers:
Many of the Ulcers fish get are related to sudden environmental changes within the aquarium. Like sudden temperature changes or waiting to long before doing a water change and then changing to much of the water. For this reason it is best to avoid a change of more than 2°-3°C in the water temp at a time, or doing more than a 50% water change. Most Ulcers if treated with an environmental antibiotic like nitrofurazone should help in the removal of the ulcer, supplemented with flake food laced with Tetracycline and or trisulfa combination {available from Tetra}. Acriflavine neutral and methylene blue can also help, as both are antiseptic as well as antifungal and antiparasitic. It is advisable to isolate the fish as soon as you can if at all possible, and then try to cure the infection. If the treatment fails, then unless the fish is of major importance for breeding purposes then the fish should be euthanized.

Velvet:
Velvet is another disease caused by protozoans, the fish will be covered with fine spots that when light reflects of the fish it looks like velvet. Your local aquarium shop will have what you need to cure this disease, most of these are based on methylene blue or copper sulphate you could also try formalin dips at 250ppm for one hour or a smaller dose for a longer period. Please note that crustacean will not tolerate high doses of copper sulphate.

Tuberculosis:
Infected fish may not show any signs of being infected by Tuberculosis for a long time and then suddenly Show signs of infection, this is mainly due to the fact that if the fish isn't stressed it mightn't show the signs but still be a carrier of Tuberculosis. This is one more example why a quarantine aquarium is of benefit if you are serious about fish keeping. For during the time that the fish is in quarantine it is possible to place a small amount of stress to the fish, and see what happens. Then if the fish does show the symptom's of Tuberculosis it is a lot easier to manage. Tuberculosis is one disease that is just about impossible to treat for, if the fish is suspected to be infected with Tuberculosis it should removed from the aquarium and isolated has soon as possible. Tuberculosis infected fish will shows signs of ulcers or cyst like growth on there bodies, these will grow and the fish will slowly get weaker and get thinner then die. Unless the fish is highly important for breeding purposes the fish should be euthanized. If Tuberculosis is suspected in your aquarium care should be taken when working in the tank for example; do not place your hand in the aquarium if you have any cuts/scratches that aren't fully healed or if you are taking medication that reduce you immune system also wash your hands thoroughly after working in your aquarium. Tuberculosis is not easily contracted but is also a very stubborn disease to get rid off.