[7thheaven]

I have received new tank from LFS.
The tank is about 100gallon(LxWxH=>125x55x60cm)
and wil be FOWLR. There is two overflow in both side
(each hole: 1 inch) and two SeaSwirl 3/4 inch
I plan to use Iwaki external Pump for water flow.
I have had 20RX already, and I will buy 20RX or 30Rx.
I can not use more wattage pump because electricity price is higher
in korea than in other country. so I can not afford it.
which combination is best?
I want to know your opinion..

(Iwaki 20RX -> 540gph/4ft , Iwaki 30RX -> 960gph/4ft)

1. 20RX(return) x 20RX(return)
2. 20RX(return) x 30RX(return)
3. 20RX(closed loop) x 20RX(return)
4. 20RX(closed loop) x 30RX(return)
5. etc...

Thank you in advance and Have a good day~~~