surface agitation w/ calfo overflow

i just got a "coast to coast" or "calfo" style overflow installed on my 40gal breeder tank. These are know to be the best overflows because of there surface skimming ability. My question is that in a tank with a "calfo" style overflow do you still want to agitate the surface or keep the surface calm? It seems to me that you might want to keep it calm as the organics cling to the surface tension of the water. This way they would all skim off into the overflow, down to the sump and into the skimmer.
Can anyone elaborate?

 

You always want to agitate for gas exchange or your pH will plummet.

 

awesome! Thanks