Hi all, I’ve posted this upon the request of @4FordFamily in order to help future readers of this thread. So currently these are the fish in my 240gal DT 5” Annularis Angelfish 5” Magnificent Foxface 4” Mustard Tang 4” PBT 4” Blue Tang 4” Purple Tang 3.5” HYT 3-3.5” Scribbled Angel 2.5”-3” Multicolor Angelfish 2.5”-3” False Percula Total of 10 fish. I also have a 50gal (45gal water volume) QT, with an overhead filter and a small powerhead. I quarantine all of my fish with 30 days of copper and 2 rounds of prazipro. All fish went through the QT process. However a year ago, there were sea urchins that were introduced to the DT. I noticed that there might be some disease that was carried but it only showed on the Mustard Tang (spots, scratching). Months have passed thinking I was safe. Suddenly, upon adding the multicolor and scribbled, velvet reared its ugly head. Here’s a list of symptoms that appeared in chronological order (earliest to latest): 1. The scribbled has powder sugar coating during the night (not noticeable during the day). 2. The PBT swimming against the flow of the current during the night (I have 2 small powerheads oxygenating the tank at night). PBT didn’t do this until recently. 3. The Mustard Tang occassionally swimming against the powerheads during the day. 4. Annularis is scratching as if something was irritating the gills. 5. Mustard and Annularis now has a fainter color than before. 6. It claimed the life of a False Perc yesterday. Looks like it might claim some more. Good news is everyone’s still eating fine. However, I don’t think I have much time if I’m going to delay. I have a plan in place: FW dip then put it into my QT (I have no access to Acrivflavine, but I do have Paraguard). I initially planned to catch only the Scribbled, PT, HYT and multicolor given the size of the QT, but upon consultation with 4FordFamily, he suggested to try and rescue all. I’m going to go fishing tonight when the lights go out, but before I do, I’d like to ask some questions: 1. Which is better? A Paraguard dip or an FW dip? 2. I plan to ramp up my copper in the span of 3-4 days instead of ramping it up immediately since fish are still relatively fine. But hopefully after 48 hours, I’d reach the minimum therapeutic dose of 0.35mg/L (I have cupramine, btw; no way to get Coppersafe; i’ve also read about the minimum therapeutic dose from one of @Humblefish ’s replies in one of the threads). Would this be good? 3. Currently, the separation between the DT and QT is less than 10 ft. I have no way to move my QT (or even the space to acquire another one). How should I go about the fallow period and treatment, such that there would be no cross-contamination between the tanks? 4. How often should I change my water? I plan on doing 5gals, 3x a week spread over the week, for a total of 15 gallons per week. Extremely light feeding. 5. Should I worry about aggression in a cramped space? (Although I’ve seen tanks in Asian countries with extremely stocked like what they do with African cichlids [am I right with this one?]) Many thanks for the replies!