Once 1.75ppm is reached you have two options:
Treat for 30 days and then start removing copper via water change or cuprisorb etc.
Treat for 14 days and then transfer the fish to a second sterile QT.
It's important to monitor/maintain the therapuetic Cu level throughout whichever route you take.
Just curios, but if copper was added after fish in, and allowed time for cysts to form ring there was no shield to stop that, how come the run time is 30 days and not 76?