Hmmm... well, I went to this site: http://www.living-learning.com/faq/magspecs.htm, and at 4 feet of head height, the Mag Drive 7 pump pushes 480GPH. Don't I need something that pushes closer to 600GPH, which the Megaflow supports? Plus, I'm trying to turn over my water 10-20 times per hour, so...