Spiffy, I think there's a little misunderstanding of what I meant to say. I'm saying that you keep only the new TBS rock in a separate tank. In your case, that could be your current 24G nano. You could get your 55G set up w/ SW, receive the TBS shipment, and dump the TBS LS into the 55, then move your nano's contents into their new home in the 55G tank after the LS settled and completed any cycling. I'm still a newbie, but I would hazard a guess that the LR in your current nano would be able to handle any small spikes that the LS would cause, and that you could just add the LS and your nano's contents in the same day and not worry.
Does anyone know if cirolanids live in sand, or solely on LR? If they live in sand, then that complicates things a bit. In order for Spiffy to be safe re: cirolanids, it would require QTing the LS too, which doesn't allow for moving the 24G contents in w/ the new LS right away.
Whether cirolanids live in LS or not, I still think you should keep the new TBS LR by itself in some sort of tank, and look for baddies on it. I'm just trying to brainstorm a way for you to use your 24G tank to do that, instead of you having to go buy a tank just for that purpose, since you said that your 10G tank will most likely be too small to hold the new TBS rock.
bobt2, how much do you feed your tank? are your various crabs getting any leftover food, or are they hungrily patroling your tank, keeping it spotless? I have all of the animals you listed except for the urchin. I think you can rule out the porcelain crabs, as they feed on plankton which is suspended in the water column, but I read over and over that crabs are obligate scavengers, and the bigger they are, the more problematic they get. My 4" gorilla crab was munching on snails and I suspect he also mowed down all four shaving brush plants that TBS sent with my package. I'm taking out all gorilla crabs I can find. I've got 1 left, and a mantis in hiding.