I'm trying to piece together a replacement system to dispose of my OLLLLLLD Jandy equipment and am planning on using Pentair equipment. However, when it comes to SWGs they offer the IC20 (which is sized for my pool) and the IC40 (which I would think should hold more, last longer, and work faster) and the price between the two is like $30(???). Why would anyone buy the IC20 if what I believe is true? Is there a fault in my logic here? Am I just crazy? Please, tell me what I'm overlooking.