Originally Posted by
JamesW
I'm a big fan of pond matrix and poret foam.
I gotta disagree with slicksta with respect to aerobic vs. anaerobic bacteria not being able to exist in the same filter though how effective the denitrifying bacteria are I can't say.
Biofilms are a wonderful thing so I'd try and find a media that doesn't need to be clean or is self cleaning. With horizontal flow through my poret foam sump, the pump side ends up being filled with a fine mulm which I remove each water change. I have 9" total thickness of poret foam and haven't cleaned it in over 6 months with no visible drop in water level across the foam.