Sorry to hear this.. Pull it out of your tank so it doesn't throw off your water params.
As for mine, I just moved my Crocea to my new tank and he is sitting on the sand. Under him is a decent size rock that he can attach to. Once he's attached, I am going to move him up to the top where he can get the most amount of light. Hopefully he will stay where I place him?!?! - Mind of their own, those clams have.