seems like the easiest thing to do would be put the clam in with the other 4 you have. that way we all win. you get you clam, all the reefcentral members can sleep easy knowing that the clam will be in a good home. why not put some other low light, hardy coral in there like mushrooms, star polyps or some thing to liven up the sea horse tank. or you can plumb you 2 gal into your 46 add the proper lighting to it and give it a shot with out telling us. that way when/if you have success you can tell us about it and if not chalk it up to a loss and keep it to your self. again, not trying to be a jerk or put you down.
~nick