I posted this question on another site with no response yet so I thought I would ask here. I have a mag drive 7 with fractioning impeller and a mag drive 5. I was wanting some more flow out of my sump and the fractioning impeller cuts down on quite a bit of flow so I was wanting to put a mag 7 impeller in the mag 5 thus making it a mag 7. From the info I have been able to gather from some reef forums is the impeller is the only difference from the two but the part # seems to only be the same on the mag3 and mag5. So has anyone else done this or know if the impeller is the same on the mag 5 and mag 7? Hopefully the more experienced and knowledgeable members here will have the answer for me.