I have a Red Sea Pharm Berlin Skimmer and I am not sure I have the air tubes properly connected 
Here is an head-on shot: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer001.jpg and a sideview: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer004.jpg and a closeup of the connections I've made: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer006.jpg
You can see the skimmer inside my cabinet here: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer008.jpg but there is no foam in the cup http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer011.jpg
Thanks for your help!

Here is an head-on shot: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer001.jpg and a sideview: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer004.jpg and a closeup of the connections I've made: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer006.jpg
You can see the skimmer inside my cabinet here: http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer008.jpg but there is no foam in the cup http://i47.photobucket.com/albums/f198/CarmieJo/Skimmer011.jpg
Thanks for your help!