Help with return pump

[theplatypus]

My initial plan for setting up the sump return was to use a Genx PC-x 30(950gph)with an eductor on a 75. I'm starting to think that no matter what steps are taken there will be microbubble problems. What I'm thinking is to make the px-x30 a second cls w/ eductor and use another pump for the sump return. With the new plan space has become an issue so I'm pretty much stuck with an in sump pump. The sump is a 20 long, 14" overflow, 1 1/2" Durso. So should I go with a mag5 or mag 7?

[tims]

do the 7, and add a control valve incae you have to slow the return down a bit
heck i havea mag5 doing the nano..

[theplatypus]

I was thinking of using the Mag5 since the 2 cls should give a base of around 24x turnover plus the addition of the penductor.