Did ya soak it first Snow? That helps a lot by the way if you wet the substrate for 48 hrs before you install it, gives the particles a chance to soak and sink. Your coral should be fine as long as you gently dust'em off afterwards.
My blue damsel tends to be an avid digger. He has covered my corals before with aragonite and the corals simply extend their polyps and wipe off the sand. They may even take the opportunity to soak up some calcium from the sand. WHo knows.
