Are these fish in copper yet? if not, I'd go ahead and dose the QT tank up to full copper.
if you have copper power, add 1.5 ML per gallon of actual tank volume. If you use that, you will be fine until your Hanna copper checker shows up.
These fish appear to be getting worse. I'm not sure why they aren't in copper yet.
The prazi can stay active in the water for up to 72 hours, but it starts breaking down after a day. by the time it has been in the tank 24 hours, it has already done most of the work and is now breaking down and becoming less effective. Go ahead and do a water change if its been a day. do the water change and then dose the QT tank with 1.5 ml copper per gallon. That will get you close to 2.5ppm. Then just confirm the copper level once your hanna checker shows up.