My fish have white dots!

Question
My tank has 2 iridescent sharks, one is 3.5 inches and the other is 6 inches. Than I have a small black fin shark that is only 2 inches. First my 3.5 shark started getting white dots and than my black fin. My black fin has ALOT! He's completely covered in them, and now my biggest shark is starting to get them too. My little oscar had these before he died which leads me to believe that these will die too if I don't treat them. Please, what do I do!

Answer
Sounds like Ich. This is very common in tanks and therefore easily treated. Turn the temperature in the tank up to 84F to speed up the lifecycle of the fish, increase the amount of air going in, and add a touch of aquarium salt. That will help out the tank while you go buy some Ich medicine.