When I start getting fish for my tank, I have a 10gal that I will be using for a qt tank. I have a whisper filter rated for 30 gallons or so, got it used for free but it works fine. What media do you guys use for your qt filters? The carbon bag inserts? I use either lava rock or filter floss in all my HOB filters, but they're all freshwater and I'm just looking for biofiltration pretty much on those tanks. Ideas?