Markk96,
I agree with Sahin that the clam looks to be stressed. Gaping is an indication.
I visited your website to get some info about your tanks specs, lighting and other equipment but saw the site is still in development and that you don't have the info listed as of yet.
Judging from the pictures of your tank, it looks like you have VHO or PC. If that's the case, I would put the clam as high on the rocks as you can possibly put it.
Maxima and Crocea's especially are the prettiest but also the most light hungry clams you can buy. Easy to take care off if you don't move them often, provide high lighting and maintain good water quality.
Let us know what your lighting is like and I'm sure we can provide you with a solution.