question about ich bumps and hypo

[dsa_mom]

Our fish are in hospital tank at 1.009 for about a week now. Only one fish had signs of ich, a white bump like a grain of salt on the body and one on the tail. The one on the tail is now gone, the one on the body has not changed in size or appearance, nor has it "fallen off" as we expected it to. Do these ever not go away? Could this just be a part of the fish's body that we mistook for ich? If it is in fact ich, what if this doesn't fall off?
Will this poor fish stay in isolation forever?

 

[dsa_mom]

Thanks for the reply--as I posted, the spot does look like a grain of salt. We will be patient and continue to watch. Hopefully, it will fall off in time. Thanks.