Sand Fleas would probably be annoying to the corals. Whenever they do swim they swim spasticly. I dont think they would actually eat the corals though. The snails I think are reef safe but I can not assure you that....
http://www.nano-reef.com/forums/index.php?showtopic=159380. and I meant coquina clams I don't know why I posted snails lol and from what I read in this thread they will eventually perish and cause a small spike and could possibly pass on parasites to your fish. so I dumped them up the road, thanks for the help though.
sand fleas (mole crab) +1 i've had some in my tank they're great sand sifters but they will prey on feeder ghost shrimp and small fish if they hang out on the sand.
Just came across your thread here on Sand Fleas/Mole crabs. I'm very curious about keeping some in my Nano to keep the sand bed churned up. I'm actually sitting on the beach in the Outer Banks as we speak. Just caught a bunch with the kids. There are tons of them, big and small. I would want to catch small ones maybe the size of my pinkey nail. I have dips that I use when I add new fish I would definitely dip them in before adding. What do you think?