I recently installed a Fluval Ps1 Protein Skimmer into my 32.5-gallon Fluval Flex. I was watching some videos on installing it and thought I had it, but the bubble/foam won't go over into the collection area. I tried pushing the collection top below the line it's supposed to be at and it still won't work. I also tried leaving it for around 16 hours, and nothing has changed. Any thoughts?