That's good that they are QT-ed. Are they still eating? How are they behaving? The garlic in and of itself may just do the job if they are still eating normally.
If they are still in fair condition and eating [no rapid breathing or overt signs of distress] you can continue the garlic and then drop salinity to begin using the hyposalinity method. In terms of salinity drop you can do this as fast [or as slow] as your fish seem comfortable with. I would use these methods before using copper, only if the fish are not in severe distress.
There have been several very detailed discussions pertaining to hyposalinity, FW dips and copper treatment resently on this particular forum. You should take a look at those and see which you feel is best for your situation.
Boy, it seems like fish always get sick when you are away! It is amazing how that inevidably happens!
[ July 01, 2001: Message edited by: Beth ]