Hmmm. Thanks for that info. I just put a larger reservoir in my WC setup and moved the reservoir to the top of the case, all in an effort to reduce air bubbles. But unfortunately it also seems to create more backpressure, because my Eheim started humming like crazy...
I may first try a large tank at the bottom (less lift, less backpressure), see how that goes. Otherwise, I'll be shelling out the big bucks for one of these babies!
Thanks,
Arjen