[whatever you do, ~don't ever target feed a clam~ that means injectng them or blasting them with phyto. you can damage the clam if you do this.
just provide plenty of light from a metal halide light, add every once and awhile phyto to your water column, the clam will filter feed naturally. other than that, just maintian your water parameters and your clam will remain healthy and grow big.
here's a pic of my crocea. i've had this clam for nearly a year.
:cool grin:]