Overflow Box Question

[Joe M]

I'm going to be picking up a 125 gallon tank soon, un-drilled, and i am not drillin it. I'm planning on buying a 1200gph dual overflow box, and im building my own sump. My question is what size pump should i use? I found a combo that came with a CA 3000 pump that does 1000gph. Would that be sufficient? It would cost me an additional 80 or so dollars to buy the box itself and a mag 12, so i would prefer the CA 3000 to work so i could buy the combo and save some cash for the other things I'll need for the tank.

Also, if the box does 1200 gph, will i need a ball valve below the box to slightly restrict the flow to match the pumps output?

I've never done an overflow box before, only built in overflows, so any help would be appreciated. Thanks.

 

[Joe M]

Also, I currently have a Fluval E300 heater on the 55 i will be breaking down. It seems to struggle a bit getting the 55 up to temp when it has had too, but keeps it nice and steady once there. I plan to buy an Ehiem Jager 300W to heat the 125 along with the E300, But has anyone ever used the E300 to heat a larger tank by itself, as the packaging claims its able too?

 

[Joe M]

bump