i really do not think it makes much difference if the bio media is contaminated,,as the fish already are. everything that will be treated in QT including all media.
what you would not want to do is use any filters from a QT on the main tank without a thorough scrub down and air dried for about a week. that's where you could have an issue.
in fact,,most folks wil just toss the bio media that was used on the QT regardless.
i don't know,,you could give the hypo a try at least you will not be poisoning your livestock..although probably at a safe dosage, but still. however, hypo is really taking awhile to work for my QT, still seeing ich after 3 weeks at 1.009 or below. i am losing hope with it as each day goes by and those freakin things are still there. i do not believe it is going to be all that great for the fish to be in hypo conditions for 3+ months so this better take hold quick.
i'm actually already thinking ahead to begin copper soon.
you must ensure to maintain the sg at the target for the entire duration,,as even 1 day will give them a chance to begin another lifecycle.
there have been low sg strains discovered so there is a slight chance that copper would be the one and only remedy.
i don't know..i have had a spot on my puffer for over 2 weeks now..the thing must be having a damn feast that it does not want to release. freakin thing... i tell ya this strain i'm dealing with is a bastard to eradicate...
good luck..........