Hi everyone I'm planning on building a 1000 gallon plywood aquarium. Currently have a 125 gallon. I'm just trying to work out all the kinks befor I embark on this journey. I'm planning on using a 3 barrel system for filtration. Barrels are 45 gallon a piece. My question is what would be the cheapest way to heat this freshwater monster?? Any help, opinions, or inight will be greatly appreciated thanks.