Okay guys I need help. I am new to sump filtration and need some advice on this stuff. I am building my roughly 4,000 gallon indoor pond in my garage and would like to know how big of a sump I should build? The dimensions will be 14 x 9 x 4 foot. I just ordered my tornado 10,000 gph pump and the liner. I bought a 25 x 30 liner so I will have left over liner to hopefully build a nice sump. The pond is going to house large fish so the filter will need to be good size to handle the bioload. Like I said I am new to this kind of thing so i need help on what I should do. Also, I need to heat it for the winter so what would be the best way to heat something like that to say about 75 F?