Just to add as velvet is often confused with ich. With ich, you can generally count the dots whereas with velvet, it represents the solar system as in the case of your tang. velvet spots on the fish that are much finer than the spots seen in Ich making it harder to catch until in cases too late to treat.
Some behaviors associated with a fish with velvet are :
- Scratching body against hard objects
- Fish is lethargic
- Loss of appetite and weight loss
- Rapid, labored breathing
- Fins clamped against the body
- rapid breathing and mucus around the gills
Fish with velvet will typically stay at the surface of the water, or remain in a position where a steady flow of water is present in the aquarium. As the disease progresses outwards from the gills, the cysts then become visible on the fins and body. Although these cysts may appear as tiny white dots the size of a grain of salt, like the first sign of Saltwater Ich or White Spot Disease, what sets Oodinium apart from other types of ich is that at this point the fish have the appearance of being coated with what looks like a whitish or tan to golden colored, velvet-like film, thus the name Velvet Disease.
Remove fish from main tank and give them a FW dip or bath and then place them into a QT with vigorous aeration provided. Treat the fish in the QT with a copper-based medication such as coppersafe. Although many over-the-counter remedies contain the general name as ich or ick treatments, carefully read the box to be sure it is specifically designed to target "Oodinium".
