2 Filters In 1 Tank

[mike_nofx]

Im thinking of adding a second filter to my tank.
It currently has on overhead filter (the kind with a spray bar) and i want to add an external canister filter.

My question is, do you have both inlets of both filters next to each other? or on opposite sides (ie. inlet from one filter on same side as outlet of other filter, and vice versa)

Tank is a 4' Aqua One filter Heres the Link, Mines the 120.

 

[diet]

on my rio 180 i have them at opp ends

 

[The-Wolf]

I have one at each end with inlet/outlet of each pump at the same end
one has a spraybar the other dosn't, it just dumps the water directly back