That's good perspective kien. Thanks. I think I was probably a little heavy with CUC to begin with. So you're right, it might have been teetering on the brink to begin with and then this incident might have just pushed some over the edge. I am seeing some life with the crabs and shrimp so that's all positive.
Ya know this has been a great learning experience. Mother Nature has a way of taking care of some problems by herself. My protein skimmer has been working overtime and has pulled out all sorts of dark nastiness. I just did a big water change and in the process checked for black sludge. It was almost all gone. I wiped it down with a paper towel anyways but really the tank seems to have recovered well on its own.
And you can bet that now that I'm done with the water change I already have sea water mixing and am making more fresh RODI water to have on hand.
That's probably the best lesson in all of this. You just never know when disaster might strike.