Brandon is talking about my dad's tank. But really, let's talk about his mom's tank.
Like Brandon said, my dad has one of those skimmers, and it seems to be very finicky. I talked to my dad on the phone today, he said in the past week the skimmer produced about 1/4" of coffee skimmate and it's still pushing a good amount of foam. Sometimes, however, it seems to go months without any skimmate until you adjust something and it goes crazy again. His nitrates are off the charts, literally. Although this is most likely due to his use of a trickle filter for many years, I can't imagine the randomly functioning skimmer has helped- DOC are DOC. I personally don't like the skimmer, if nothing else, b/c the brand isn't distributed widely enough to have any real feedback, good or bad, to get an idea of the brand's performance. I would stick with brands that are tested, either by a wider market or an experienced reefer you trust.
Is your skimmer in an established tank?
Just curious- do you speak as much German as your name implies?