I have a bubble magnus NAC6 on a 90G heavily stocked tank, and it doesn't pull out that much either. The system is a 90G growout system for clownfish. It's fed heavily around 5 times a day. Theres over 500-600 fish in there.
Although sometimes the skimmate smells, it normally doesn't, and has a tinge of grey/yellow/brown color to it. The neck of the skimmer is constantly brown and gummed up with crud. Maybe the answer to this would be a skimmer neck cleaner..
I've had this skimmer for 2 years or more, and it's consistently been the same exact way.
I've come to the conclusion that bubble magnus is not a great skimmer. I have an SWC cone skimmer in my broodstock tank, around 50G system, and it has a really dark skimmate that smells pretty bad. That tank is fed once every other day.. constant water changes on both systems...