Hmmmm, pods make it thru the return pumps just fine whether a 55g or 500g with a sump as long as the flow through the sump is sized to the tank, our 55g has about 17g sump with a fuge area that works just fine and a flow of around 214g returning to the tank, our skimmer a PM Bullet1 is running exterenly with the out put plumbed into the sump, and a Sedra 9000 in the sump feeding it, a small baffled off fuge and then our return fed by a mag3., am happy with it and works great