Hi, I need advice about my Juwel 3.0 skimmer in my Juwel LIDO 120. I am not satisfied with the skimmer. It produces a bit of gunk at the chamber leading into the collection cup, but doesn't really produce a skimmate. It just doesn't seem to be skimming well at all. Does anybody have any experience with this skimmer? What advice can anyone offer? Will getting rid of the skimmer and designing a sump with another skimmer work? Does anybody have experience with sump construction in this tank? Will appreciate any advice. Thanks