I have a tiger shovelnose, 3 red belly pacu and a giant gourami currently in a 300 gallon. Long term plan when I move house is to have a 10x4x2.5 tank built but at the moment i'm looking for options for when they outgrow this tank. I'm thinking of using an above ground swimming pool, i've seen one which measures 12ft across and 40" high holding 9,150L. Does anyone else use one for large fish? What would be the best way to filter it? It would be in a garage, would it be best to use heaters to heat it or would it be cheaper to heat the whole garage instead?