[webdr]

Im building my first sump and doing a slight upgrade from a 29 tall to a 37 or 40 tall.
I will drill the tank at the top, no overflow box or stand pipe.
What size overflow tube should I use for best flow? What gph return pump?
I have an aquac ev120 with a mag7 and the sump is a 20 gallon long if that is useful info.
thanks...