What size return pump?

[firefightered]

Ok guys and gals it's time to start thinking of a good return pump for my 75. I will be putting in an "Bean Animal" type overflow with 1" bulkheads. What size return pump would you people suggest? (GPH wise).

 

[aslmx]

I have a mag 5 and it seems to do fine but all I use it for is return and no equipment running. I might go to a 7 when this one breaks but that could be a while because the mags are good pumps.