Where does my bio filter live in a QT tank?

I thought the bio filter needed some rock to live on, so if a QT has no rock, how does it stay cycled?

I run a AC50 with filter/carbon. Is that filter enough media for the bio filter to live on or should I add the ceramic rings to it for some more living space, if that is true?

What if someone doesn't use ANY powerfilter/skimmer but just water changes, where does the bio filter live?

 

Your bio filter lives on the existing surfaces. You can provide more surface area by adding PVC pipe, perhaps add some sponge or bio-balls.

These are the anaerobic and aerobic bacteria that complete the nitrogen cycle. While you are not providing much medium for anaerobic growth other types of nitrifying bacteria colonize the walls of the tank and any surface.

 

Thanks, I do have some pvc pieces in there along with my sponge in my AC50.