Well, I thought I'd update everyone on the tragic state of my tank at the moment (people in Chat already know).
Everything was great! We were fully stocked (one clown, one firefish, one yellow clown goby), the corals were doing great, nitrates were staying low, and then my wife decided to clean her filter media. I'm not exactly sure what media it is, but she followed the the instructions, which included soaking it in bleach for 24 hours, then dechlorinator for 8 hours, then rinsing. My guess is she didn't rinse well enough, because when we got home from work, most everything was dead.
We got all the dead fish out, took out the dead snail (only one died), took the media out, did a 100% water change (then another smaller one later), and left it for a while to see if any of the corals would come back (they all looked awful). Over the next couple days the xenia completely died off, so was removed, but the polyps, star polyps, mushroom, and hammer all came back. The mushroom and hammer don't look quite as good as they did before, but are getting there. We're going to run it without any fish for a while, to make sure everything is ok. Hopefully it will be, and we can get some fish in there in a few weeks.