Absolutely, however our systems aren't outfitted with UV. they would require a good deal of replumbing to fit them in. Bleach is the way we went. We have 6 750 gallons and 3 240's. I will be doing one at a time since we are in no rushWouldn't running a UV eliminate heterotrophic bacteria in your QTs? Of course, it would also remove the CP but should leave the bio-filter intact. Perhaps something to do in-between batches of fish. Otherwise, I'm assuming the only way to counteract this problem is to break down the QT after CP treatment or in your case with a large QT, sterilize it with bleach.

Obviously, nothing can be reused from the treatment tank for the observation tank to prevent cross contamination.
. Do you need to soak the sponge in bleach, dry, then vinegar, dry, then rinse and ready to apply new bottled bacteria or let set in tank? (I'll have to do bottled most likely. Unless I put into my new set up which isn't here yet! Hehe
It doesn't make any sense for him to be able to sell it for 18 cents/gram when the going rate is $5-6/gram (due to a shortage). I also have more faith in the purity of CP bought from an American, Canadian or European pharmacy ... as that CP is meant for human consumption (to treat malaria) and thus, there would be severe criminal and civil penalties for watering down that stuff. 

