What GPH rating pump for 120 gallon Tank

[Kbdeprima]

1700gph is way to big for a 75g. Are you running a basement sump?

 

[scooter31707]

I am assuming you are asking about the return pump/flow. That Mag 9.5 is way stronger enough for that water volume. You want to reach for 3-5x turnover through the sump.