Tunze DOC 9005/9010, How do they work?

[DogfoodEnforcer]

im just wondering how the DOC skimmers work. is the intake at the bottom or top?

is there some way to attach some form of surface skimmer onto it? im really interested in getting a DOC, but i was hoping for something that skims from the surface.

has anyone modded one to skim from the surface?

 

[FOREIGNER]

as far as i know it is not possible to surface skim with the 9010, the intake is locate towards the bottom of the skimmer, however it is a great skimmer and highly recommended