there are different schools of thought on this, but i think your drawing would work with one minor tweak....

i typically suggest (and build) sumps/fuges where the tripple baffle (bubble trap) is the last thing the water goes thru before the return section. also, unless you plan on adding an auto topoff of some kind, you will have a hard time keeping up with water replacement because all evaporation shows up in the return section and the one you have drawn is pretty small.