I just placed my fish back into my DT after 9 weeks of letting it sit fallow. I had an Ich outbreak so, I moved my 2 Percula clownfish and black and white Heniochus to qt. The only things left in the dt were 2 turbo snails a horshoe crab and a skunk cleaner shrimp. Nothing else was added once I removed the fish. I had them in copper for 6 weeks before I started to remove copper from the qt I then left them in there for another 3 weeks. After 9 weeks I moved them to the dt and within 3 to 4 days the heniochus had white spots on its dorsal fin again. I am so confused and about to give up. I have been told many times that if you let the system sit fallow for just 6 to 8 weeks it will kill the Ich cause it doesn't have a host. Well I left it for 9 weeks to be safe. I also measured the copper levels everyday with 2 different kits just to make sure there was the right amount of copper in the qt. How can they have ich again? It should be all dead by now. I bought a UV sterilizer and I am soaking their food in Garlic Gaurd everyday. The heniochus doesn't look good. Not sure he will make it. Nothing seems to rid my dt of the ich. I am about to either pay someone to fix it or give up! Any advice would be appreciated. Here are my tank parameters, ph 8.3 - 8.4, sg 1.024, no nitrites, no ammonia, nitrate 40ppm( I know it is a little high), Alkalinity about 3 meq/l. It is a FOWLR tank 40 gallon breeder. Thanks for any advice!