I really like the G3 I'm using on this tank. Of course being a compulsive DIY guy I had to tweak it a little.
Added/tring Growstones http://www.growstone.com/about/
as a bio-media. It's an interesting product. I'm using then in my Aquaponic Grow bed. They seem like they might make a great filter media. Here they are along side the Ceramic media supplied with the G3 from Fuval.
I seldom use Chemical media and having a perfectly good cartage not being used was making me crazy. So I decided to add more Bio-Media area.
The cartage has a divider so I had to cut a slit in the foam to fit. i used the bottom gasp as a guide as I used an electric carving knife to cut the foam to size.