I feel so terrible!!!!! I just added a bit of freshwater to the tank after some evaporation, and to escape the flow of water, my sea star (only tank inhabitant at the moment) scuttled away. All fine, I thought. Then I saw the majority of one of his arms on the tank bottom!!! Looks like maybe he ripped it off on a piece of live rock maybe? So now he just has a nub... What should I do? Will he be okay? And a silly question but...should I remove the arm? Will it just create ammonia, or will he eat it or something?