Well, I don't know if you've read any of my other recent posts, but I ended up losing all my fish. I took them all out to treat, but I didn't have a QT set up, so I had to set them up on the fly... I used some tank water, some freshly made water and did water changes often to avoid the horrors of the cycle process. The powder blue did really well in her own QT, the ich was gone and she was doing well. The other fish started getting a fungus. I tried treating them, but they didn't recover. I think it had to do with the uncycled QT. I kept the ammonia down and the nitrites with water changes, but they started getting the body fungus and died off one by one.
This was in the larger QT. After they died off, I moved the powder blue to their tank, after a water change, because I couldn't keep the ammonia and nitrites down in the 10G tank. The larger tank was cycled by then, no ammonia or nitrites and about 20 nitrates. I used carbon to remove the medicine and moved the powder blue over. A couple days later he got a reinfestation of ich and just wasn't strong enough for the second round of treatment.