I am setting up a 55 gal reef tank with a 10 gal sump under it. It needs to travel up ~4 feet. I dont know how much flow Im looking for, im quite clueless and I am also going to have a HOB overflow box, can anyone help me choose which one as well? I know some are rated for always 1000gph and some only like 200 so I do now know, please help me. I am planning on having one powerhead as well, the current usa 660 GPH wave pump. Any help would be great.