I was wondering if anyone knows, is there such a thing as a battery powered filter? It would be totally amazing for my betta tank, which has been moved to an awkward place across our hall-space from the nearest power outlet. A battery powered pump would work too. How much, where to get it, and so on would be appreciated. Oh, and unfortunately I don't order things online so I'm limited to Wal Mart, Petco, Petsmart, and lfs's. I don't remember ever seeing any, but I could have missed them. Any advice?