If I may offer a single data point--I treated my melanurus wrasse with API General Cure in combination with hypo-salinity of 1.015 SG for ten days to rid him and two other fish of potential flukes. (I was never able to identify any flukes conclusively but a clown had fluke-like symptoms that I felt I needed to deal with first.) All three fish then went thru 20 days of CopperSafe at a therapeutic level followed by transfer to a sterile HT in another room because I did not want to push my luck with the wrasse in Cu any longer. (This was my first QT process.) The wrasse did fine thru the entire treatment process. I also provided the wrasse with a dish of sand, which he spent on average 12 hours a day in. I am two months down the road now and all three fish are doing great in the HT. My sailfin tang had classic Ich symptoms, which prompted the Cu treatment and DT fallow period. They will be returned to the DT in the next couple weeks. I am letting a purple firefish and a small royal gramma, who went thru TTM and Prazi, get settled first.