I have a 45 gal Red Sea MaxE 170 and a 25 gal sump. I am looking to replace return pump looking at eheim but not sure what size I need. I have about 4ft of head loss. I am guessing need 5x return rate so looking for pump that would do 225 GPH at 4ft hight that correct? I don't see where theres a chart though for this.. thanks