Why are the REMAINING goldfish in My family aquarium bleeding though their scales?

Sorry, by now all are infected. It started when one of the fish was sick and it was contagious. You pour the liquid medicine to slow, improve , etc the tank after a through cleanup. However, it will take a very long time for the fish to be its former self again. So my suggestion, give them away to a school, etc. and you start all over again.