Running a bunch of hamburg mattenfilters or do you use the foam for other purposes?
Yep! I put my first HMF in a 125, and I love it. I also have (not all are set up yet) a 90 on it's way, a 55, a 40B and two29s. They're all getting the HMF treatment now ; ) The leftover bits make great prefilters/screens on HOB intakes, as well as powerhead sponges. It was sewingalot's thread that got me started.