ich and copper

So i think I might have ich. Tried to quarantine the fish first but she was not eating in the quarantine. After being in the display she was swimming around and eating like a pig.  I have had ich before and copper differently works but not with out some lost. Problem that I seem to be having is they don't eat after going to the full dose and dont really seem to recover. Here are my ideas.

A)  fresh water dip

B) Copper
     1.Keep the dose at half which would be 2.5 and not the recommended 5.
     2. Only keep her in there for 5 days not the recommended 14
     3. After the first five days change tanks no copper and see how she is doing.
     4. No substrate but maybe a little for a bed. She really seems to dig the sand in the display.
     5.  Throw away the sand that I use for her bed.

C) Hypo salinity never tried this but maybe they will still eat.

Trying to fatten her up right now. In case I go the copper route, but I dont want to lose her. She a gorgeous Harlequin tusk yep she is from down under.

What your thoughts?

Anybody.

Thanks for the reply. How often are you switch the tanks during the 12 days period.

Breathing fine no stratching and no sheen. She has had the same four dots on the pectoral fins and tail. Since I got her last Wednesday. Might try the tank switch just to be safe. Thanks again for your help. Good luck with the move.