I was just wondering. My skimmer is dialed in and removing smelly stuff. I have the model that has a drainage tube from the collection cup. I'm getting small amounts of brownish water, but the inner tube in the collection cup is constantly caked with goo, even though I get some foam spillage. It seems the foam should be carrying the goo out to the collection cup, but it stays in the inner tube. It's not going back into the water, but I have to clean it like every 3 days. Do I need to increase air flow to carry the stuff out of the inner tube or is it working properly?