I have had my Crocea Clam since June now, and he seems to be doing fine except he used to be attached to one of my rocks. He has since detached and will not reattach anywhere. I moved him from his original rock and up a little in the tank. He keeps ending up on the sand bed, and I'm not sure how he keeps jumping off like that. I have never seen it happen, just come home to it constantly. I feed live phytoplankton about 2x a week, and turn the skimmer off when I do. When he attached the first time I left him completely alone. So I don't think I damaged his foot....not sure what is at work here.