QT Bio Media setup question

Hi all
I'm setting up a another tank and at the same time looking to setup a QT tank to treat some fish while I get the new tank going. Im reading so much information I'm now confused. The hospital tank I am using to treat the fish(two clowns, both very small about under an inch) is a 15 gallon. I have all the equipment needed but am confused on the bio filtration.

I have read some people saying that I need to let it cycle for 2-3 weeks, others saying throw a sponge in the sump for 5 days, and some others saying that using copper, and prazipro make it pointless because they will destroy the bio filtration. Since I am going to be treating with meds do I need to cycle the QT tank? or will doing water changes with newly made up saltwater daily be sufficient? I.e. if tank is 15 gallons than aim for 5% daily or .75gallons a day while watching for ammonia?

 

My clown goby came down with ich about 2 weeks ago and I have been treating all my fish with cupramine by Seachem. Seems that stuff works great. BUT, when I saw the signs of ich I pulled all my fish out and set up a HT immediately and I didn't have the means of a cycled tank. I have the basics that I needed and have been treating the fish, doing water changes about once a day if not every other and keeping an eye on them and everyone is still accounted for and eating. So I am happy about not having a loss and everyone being healthy and the signs of ich pretty much gone. Going to keep treating another 2 weeks with cupramine to be super safe and then add carbon to remove the cupramine and QT'd for another month that way I meet the time frame of at least 8 weeks of my DT sitting fallow.

Just a bit of background if you can pull any info from that. Basically, I would say that it wouldn't hurt if you cycled the QT tank but if you do treat it with meds I believe that it kills the beneficial bacteria, but do water changes for sure.