First I wanna say.. that I am not suggesting that keeping it under pc's is a good idea.. im just telling you what experience i've had (so far).
I have mine about 10 or so inches from the BOTTOM of the tank. It has burried itself in a rock.. I'd personally like to get it higher but the tank its in really has a 'lack of rock' situation going
Its in a 55 gallon tank with 4 65 watt pcs.
My suggestion to you to try and give it every chance possible would be to get it out of the sand and place it as high as possible on a rock and make sure that it is getting FLOW directly to it.. not strong flow but some sort of flow to make sure its able to get its food.
Feed various planktons to your tank to make sure its getting food. Dont get crappy phytoplankton either... get the good live stuff to make sure that thing is as healthy as possible.. and keep your calcium where it needs to be.
and marry that girl you idiot... 6 years??? she bought you a clam??? dude.... whats wrong with you?