I have read sup many opinions online and feel more confused than when I started. Last week I moved my fish from a90 gallon tank to a 100 gallon tank. My jack dempsey who I have had for almost 2 years and is about 5-6 inches just popped up with a white dots. Looks like I sifted some flour over her back. She has never had this before. None of my other fish have any of the same signs or symptoms. I have a 10" oscar, 2 small parrot fish (4" and 2") and a small shovel nose catfish and a 5" pleco. I keep reading to treat the whole tank. Since my catfish is scaleless (right? ) I know to be cautious with what I put in the tank. I have started raising the temperature slowly. It is now at about 84° and I just turned it up another degree tonight. Sounds like med free is the best first defense. But I hear mixed reports on aquarium salt. Is the salt just supposed to help with then getting oxygen? What is the chance this ick could kill my jack dempsey or spread to my other fish? Is it a fast killer? I have never had to deal with an infection like this before.