I have had good results with my Reef Octopus 150sss skimmer for the past year and a half. However, it has become difficult recently to pull the waste cup off to dump it. Feels like it takes 80 pounds of force to break the seal and pull it off. Any suggestions? The white gasket looks normal. And the acrylic opening looks clean. I tried lubricating the gasket with food grade mineral oil a few days ago, but big mistake. The skimmer has been foaming like crazy but has calmed down now.