Hospital tanks only treat fish not disease??

[Red5]

I have a 20 gallon nano with 1 Banggai Cardinal, 1 Royal Gamma 25# of live rock, various snails, crabs and 1 coral banded shrimp. I do not have any corals yet as I am still learning the basics. Recently my Royal gamma came down with ICH so I removed him to a hospital tank and treated him with copper, after about 2 weeks and no sign of ich I returned him back to the nano. Now 1 week later I am noticing the white spots returning. The Cardinal seems to be doing great and showing no signs of the disease. So does this mean the disease is still in the tank? If so than if I remove the sick fish and treat him in a hospital tank am I really doing any good if the disease still remains in the nano? If so how do you treat the disease that's still in the tank? :confused: Any info? My water quality is great and there are no other signs of stress.

[smpolyp]

Hospital tanks have fish for about 1 month to cure most all infections. Also keep your copper medication up to .15 ppm min. for 3-4 week if you want to eliminate cryt (ick). You can contact Billsreef on the the marine fish D thread for additional help.

[billsreef]

You need to remove both fish from the nano and treat them for 4 weeks. The nano needs to remain fishless for 4 to 6 weeks in order for any ick cysts to starve out. In this way you can eliminate any ick from the nano and also the fish.