I had this go horribly wrong and lost a blue tang. I am trying to see where it went wrong. I had a blue tang being quarantined. When I bought him he was visually free of ick and very agressive eater. After about 10 days of observation I noticed very fast breathing and some flashing. His appetite was very low and spent alot of the time hiding. I have been following brs videos about the 80/20 method, they mentioned the vast majority of fish will have gill flukes. They mentioned that prazipro was super safe for the fish. I was starting to suspect flukes and did more research on freshwater dip method. I used seachem marine buffer with rodi water and let it mix and reach the same temp as the tank. I put the blue tang in and got him out before the 5 min timer. He was breathing very hard and it started to lower towards the end of the timer as I was getting him out to put back in saltwater. He was looking rough. Instantly I held him and tried moving him through the water to help water get through his gills. He unfortunately didn't make it. All the research and videos I watched from marine biologist and fish farms stated this is not a lethal method to determine flukes and help with them before using medication. Is this usually lethal or did I miss a step? I have been in the hobby for over fifteen years. I am jumping into setting up a massive fish tank with very high end fish and need to be able to properly quarantine and medicate fish.