Ammonia is not going to be an issue, I have dosed ammonium bicarbonate a few months due to low nitrate values (more on Randy's ammonia-thread) - my maxima is doing better than ever.
They do enjoy high PAR, mine usually used to lean towars Hydra's instead of Prime's. The clam will move itself towards the light (if not completely fixed to the substrate), that is one of the first signs you might want to have some extra punch. Pretty much the only time my clam has been unhappy has been during tank move, when it decided to make sexy time making the whole tank white.
Good luck with your clam, below is my +10 year old fellow (serves as a couch for blenny & gobies