I've had fish for 30 years or more and have always done filtration the easy way - connected to a plug. However, I'm spending a couple of months in a home without steady mains electric, and am just wondering if anyone has a good solution? There are no plug sockets in this house, so I've got to attempt a battery version. I have two small tanks, 25L and 55L. I'll come across as utterly ditsy here, but never mind: googling 'battery powered filters' has generated lots of filters that have plugs, and highly complicated home-made devices that involve soldering irons and all sorts of things that are beyond my scope of experience. Neither of these extremes is going to work. Does anyone have a simple solution? Can a fish tank be done without being connected to a wall?