I'm having no luck filtering out very fine particles in my 50. I have a Fluval 206 and Tetra Whisper 45 HOB and keep seeing fine waste particles floating around. I completely cleaned the 206 media and I replaced the foam blocks with new. I bought the Tetra HOB and have the Bio filter installed. I'm trying to engineer a contraption with 180 ML filter media bag to catch the outflow from the HOB. It will look like crap in the tank but I figure I will only need it for a day or so after a water change/gravel cleaning. Anybody have ideas?