First of all, what are your water parameters? Sometimes when cycling a tank, especially with fish, there can be sudden,deadly spikes of either ammonia or nitrates. This is why a lot of people find it more humane to do a fishless cycle.
I would test the water twice daily (once in the morning, and once at night) until there are no more spikes and the ammonia and nitrates read 0, which means the cycling is done and there are sufficient BB in the tank to handle the bioload.
That does mean you'll still need to change the water on a weekly basis to get rid of the BB's waste product, Nitrites.
With that said, I would add Aquarium Salt to the water in the hospital tank (1 tsp per gallon). Keep the fish in the Aquarium Salt laced water for no longer than 10 days (any more exposure will damage their kidneys and they can bloat, and get dropsy). Keep in mind to change the water every 2 days or so to keep it as clean as possible (and don't forget to add the proper amount of Aquarium Salt to the new water).
Last edited by TheCrabbyTabby; 04-28-2013 at 04:20 PM.