Prazipro is reef safe except for feather dusters and other type worms. I called the company and talked to them. No problems with corals as well.
With that said, I had a 12" Passer Angel that I bought, put in main tank (I did not have QT big enough) his eye's started to cloud up. I did not want to treat the main tank unless I absolutly had to.
I did fresh water dips, started at 10min 1st day, 2nd day 15min, 3rd day 15min, took two days off, next dip 15min. The first dipped looked liked it snowed in the bucket. I was ticked that I bought a fish that was that invested with flukes!!! Yes his eye was a little cloudy when I bought him.
Anyway.... the fresh water dips did the trick, but I did buy enough Prazio Pro to treat my main dispaly. 325 gallon. I have it as a back up.
Angel is doing great, after being fluke free for 1 1/2 months. No other fish in the tank showed any signs of picking up flukes.
Again, I would try to treat the one fish that has them, than treat the tank.
Good Luck