Has anyone else had the experience of killing every Acanthurus tang when they dose Cupramine at the recommended level? I killed 3 in qt over the course of about a year when I treated at their recommended 0.5 ppm (by recommended dosing and then testing). Once I lowered it to 200-300 ppb (by testing) I never lost another tang and I also never had trouble treating ich. I never used anything like Prime but perhaps my pH was causing the Cupramine to be more toxic in the same way Prime would? I hadn't heard of erratic swimming being a symptom of Cu toxicity until I just came across this thread. Each of those PBT tangs did indeed swim upside down and look very disoriented prior to dying (at the time, the only ideas I could find was that it was poisoning from cyanide collection).
