I have ordered another 150 gallon, which i think equals around 180 US gallons. I have decided not to use the sump, i'm going to use externals instead. So for a 6x2x2 do you think 2 Eheims or just the 1 fx5 would be best ? I'm still not too sure what will be going in it yet though 
Thankyou.
Thankyou.