Bad news. I have been having a lot of trouble getting my clam to attach. About a week ago i got fed up with picking him off of the sand bed 3 times a week and decided to investigate. It turns out he had already attached him self to a tiny piece of rock that fits just inside his shell so he wouldn't attach to anything else. I decided to try glue just one half of his shell to the rock so he could still open and close. I had to go out of town for a couple days and apperently it was still restricting his movement or he was fighting against it, i'm not sure. It was already dead when i got back and tried to take him off the rock because it wasn't looking good. I feel terrible now but i didn't know what else to do. I guess i won't make any changes to my tank if i am not going to be there to watch it next time.