Drilling A Tank

[Filsby]

How much surface skimming/water movement could I expect with simply drilling the side of an aquarium and overflowing directly from the hole?

Would it be better to drill the side and also have some kind of overflow/baffle in place?

 

[duanes]

I always drill the side and use an upturned PVC elbow where the water exits.

how much the surface is skimmed has as much to do with pumpage and flow, as to the type of hole.
I like at least 1.5" PVC so I can use a higher powered pump, without worrying about over whelming pipe diameter, or being plugged up with plant debris.