What kinda lights you got? That staghorn needs a lot for his shell to grow. It's coral and has to grow with him. Good luck with that. Neat how he'll always stay on the sand bed since he can't climb rocks.
I have seen many of the staghorns move into a "normal" shell discarded by others. Hopefully yours will do fine.
"Life may not be the party we hoped for but while we are here we might as well dance!"