I do have a QT set up, but I don't let it run 24/7. Thankfully, I haven't had any problems to where I had to transfer any of my existing fish over. My QT is ONLY, at this point, for new members. I will start the QT up, drip acclimate the fish, and in they go for 4-6 weeks.
my QT consists of a 20g tank, a heater, small power head, HOB filter w/ bio wheel, and pillow floss for the media. that's it