Yeah, these are all issues being caused by just buying nice looking fish without doing the research on them. These are fish that need much larger tanks and are a great sign all in all of moving way too fast. Nothing good comes fast in this hobby, other than eating people's money. This can be seen easily that we are medicating a tank directly. If this was a copper based medication that copper will now have leached into the rocks in that tank.
In general, these are all fish that will most likely need up being returned at this point and sitting down to figure out what it is that you want to do in this hobby so a system can be set up to success rather than the current shotgun approach.