When you setup a QT tank you don't have to worry about putting in any type of biology filtration. What you want to do is fill up the tank with water, you can take water from your main tank. Place in some type of pvc or rock, so the fish have places to hide. Then add either a filter, air pump with air stone or a power head so you have water movement and more important water surface breakage. Final put in a heater and you now have a complete QT.
Also you don't want to feed a lot, this will cause an increase in ammonia. The fish don't need to be feed all the time and should be fine with being fed every other day. Also you can do small water changes each week.
Remember a QT is not only for seeing if a fish has a disease but to give it some down time, from being moved around a lot, before being place in the main tank where it could be attack or stresses from the other fish.