Ok, I'm slowly toying with thoughts on the PFK cube stuck up on top of a wardrobe unused for months. I don't want anything high maintenance which leaves low light (likely the original 11w) and minimal water changes if possible. Can this size of tank survive with a water change every 3 or 4 weeks? What external filters are suitable without being too big? I have small HOB for the tank but in truth it is hardly worth having, the filter media space is negigible.