I've got a Penguin 100 running on my 46g, just to have a "seeded" filter to switch over to my QT. I run the blue GAC
pad along with the BioWheel. I rinse the blue pad really well in my "old" water every week when I do a PWC
. I change it out completely after 4 weeks. I also run GAC
in a HOT Magnum250, so I'm not overly concerned about the little amount of GAC
in the Penguin filter not being any good after a couple weeks. I'm mainly keeping the blue pad in there to make sure food/poop/gunk doesn't flow across the biowheel and pile up on it. Nitrates are at zero, but my bioload is pretty low - just a clown.