drop the salinity and run a uv for a while, make sure your fish are eating youll be fine. stay away from copper theres no turning back once you use it.
AgreedGarlic doesn't kill Ich, it may stimulate the fish to eat, but it doesn't kill them off or keep the fish from getting reinfected with ich again. Lowering the SG only works when you drop it below 1.009,(Hypo) anything else doesn't really do anything to kill off the ich or from keeping the fish from getting reinfected again. Running a UV will keep the ich, and other parasite, in check some what but it doesn't remove them from tank. Cleaner wrasse and Cleaner shrimp don't remove ich from fish, especially since the ich is usually deep inside the fish, and you only see the white spots as it goes into its finally stage before it gets ready to start over again.
Can you have a tank ich free? Yes you can.