sand sifters in an ecosphere

i am making a saltwater ecosphere (i won't pay $300 for a couple shrimp and a plant in a glass ball). i decided i would go to my local beach and get some water and some sand from their. i was think about getting sand sifting crabs (sand fleas) to put in their but i never found an article whether or not to put one in. this ecosphere would contain algae and whatever microorganisms happen to be in the water i collect as well as creatures such as sandsifters themselves that would be in the sand. would a sand sifting crab survive in an ecosphere (it would be the size of one of those tomato sauce jars)?

forgot to mention i would be buying a plant so can anyone recommend a plant?

 

i dont think it will have enogh food or space