Just lost a royal gramma in qt to what seemed to be some sort of bacterial infection. The fishes tail completely disappeared over the course of 24-36 hours and it had open wounds develop before the end on its tail and side plus another fin had started to decay. Should have taken pictures but there was no other marking on the fish other than flesh decaying and fins decaying. I had just put a fish through this qt tank less than a week before the gramma was put in. It was in qt for a couple days short of 4 weeks with zero symptoms and still after a tank transfer and another week in the dt it’s all happy and healthy. I made sure everything filtration wise was clean and did a couple water changes that week to get rid of any left over nitrates. I was dosing 1ml of prime per day the first three days as a precaution but never had ammonia show up. Then Sunday I tested for 0.2 ppm total ammonia which should still be well under toxic ammonia levels with a ph around 8 but did a water change and dosed 2ml just to be sure it was good. The store I bought it from seemed like there were trying to blame the seachem prime for hurting the grammas slime coat and opening it up to the infection. They also said they treat there tanks and have had no issues with any of the others they have sold. So after that little rant my question is has anyone ever experienced seachem prime deteriorating a fishes slime coat leading to tail loss and flesh wounds or is it more likely it was a nasty bacterial infection being held at bay by their medicated tanks?