I use the stock pump in addition to my maxi-jet pumping up to my fuge, so basically about 20 more gph than stock. I still don't think I have enough. I stead of replacing the stock pump with a more powerful one, I would keep it and add another pump. That way you get more flow without having it concentrated, which causes sand storms. If you do add a more powerfull pump, definately add a divider to split up the flow.