Dammit!
I knew I was looking for trouble and I found it. My new Harlequin Tuskfish has Ich and he's in the main tank.
I had been looking for an Aussie Tuskfish and a Chocolate Tang, and had put the word out to several suppliers. As luck would have it, two different suppliers came up with the two fish within days of each other. I didn't want to quarantine two large fish in a 20 gal QT at the same time, (figured that was asking for trouble) so I decided to put the Tang in the QT and the Tusker in the display. I was uncomfortable with this as I always quarantine new fish but Tuskfish are supposedly quite hardy, and I thought it was the better choice of the two, as Tangs are such Ich magnets. He looked great, nice colour, fat and healthy with no signs of disease. So now I have a $200 fish with Ich in my tank! In hindsight, I should have turned down one of the fish but I felt guilty refusing one after they brought them in specially for me.
There's far too many fish to remove and quarantine. I've just done a 25% water change and siphoned most of the substrate out. I'll run a diatom frequently and up the dosage of garlic and Selcon. He only has a few spots on him and none of the other fish show signs yet. Hopefully I get through this without any casualties and just live with Ich in the tank. What do you guys with large tanks and lots of fish do when Ich appears? I could hook-up a UV sterlizer I guess. If worst comes to worst and the Ich becomes a real problem I'll have to buy a larger QT and remove all the fish. Suggestions? Anything else I can do?