Well good news. I just checked the 72 gallon and the fish are doing much better than this morning. They've really perked up and are all eating. I'm not sure what stressed them, but they've seemed to calm down. I feel like the Fowlers tang started the outbreak, so I've taken him to my office tank which is a very stable system and only has a couple clownfish and wrasses. He will stay there until he gets over the ich. Hopefully he will, survive. I've only had him a few weeks, so he hasn't really acclimated fully and built up the resistance to the ich. The others I've had for several months or years, so they should be able to stick it out in the tank they're in. I don't like medicating alot, so tomorrow I will do a huge water change in the 72, run a little carbon on it, and then reconnect it to the system. I think they'll be better off in the superior water quality of the large system, rather than that of the isolated tank and copper. I've also siphoned out all the gravel in hopes of limiting the spread of the ich.