i have been at this a long time.way back there was no qt talk. just oh you have ick raise the temp and cross your fingers.imo over the last ten years disease has become alot more prevalant than it used to be.seems alot more fish and even corals have something on them.it seems even harder to get rid of it .maybe ich for example is more resistant than it used to be to treat.i have a 33 tall qt .it is always running.hasnt had a fish in it in 6 months but i ghost feed it.if a lfs says you dont need a qt dont go there anymore.they would love for you to buy a diseased fish that wipes out your tank so they can sell you more fish .yea i said it