Say if I wanted to make a pond filter out of a trash can, what material would I have to use to have a good working filter. I’m not sure. I’ve heard many things such as bioballs and lava rocks and filter pads. Also for a 900 gallon above ground pond how many gph pump would I have to have? I live in central Florida and and it gets very cold in the winter, sometimes down to 35°, if I was to put say peacock bass or a fish from south Florida in there how would I heat the pond during the winter to raise the temperature by at least 10-15°, if possible. I’ve heard peacock bass die if the water temperature gets under 55° so I would have to get it as close as I can to that. I would think maybe a small pool heater? Thanks in advance.