Get yourself a cheap HOB
filter fill it with poly-fill hang it on your main tank for a week or two this will give the Bacti time to grow in the floss then when your ready to QT use the water from your water change to help fill the QT tank A few pieces of PVC
pipe will give fish a place to hide reducing stress
When your done with QTing toss the poly-fill and clean every thing with a vinegar bath refill the HOB
and put it back on the DT to get it ready for next time.
Most people create their own problems by not following the basics and refusing to stock appropriate to their system. Gregcoyote 2013
SPS = Stability Promotes Success