how long to wait before dipping

[fullburn]

I just purchased my 1st little max clam, put in tank 2 days ago but it doesn't seem to be responding, shell opens but mantle does not extend. how long should I wait, is this normal or should a fwd be considered before it's to late

 

[Scuba Dog]

If you feel like its pinching, please post a pic.....dip it asap the earlyer the better, the longer you wait the more chance the FWD will kill the clam...