With any skimmer, the only thing that really makes the amount of gunk flow is the amount of bubbles the air intake makes. The method of air to water ratio is different for every skimmer, but make sure that you are at least making bubbles, after that, max the bubbles out by messing with the intake valve. If you don't have one, adjust the water level so that the bubble line is a little below the top of the collection cup. this allows the "crud" to detach from popped bubbles and collect on the plastic or whatever material the skimmer is made of, creating a nice gunk. research how the skimmer works, once you do that, the method you take to fix it will come automatically. Good luck bud!