I just went through EXACTLY the same problem with EXACTLY the same fish. I hate buying fish from walmart, they are always so over stressed. I used quick cure and it didnt work. In fact I think it killed my fish. dr_girlfriend told me to raise the temp to 86 and add 1 tablespoon per gallon. It worked but a bit too late for most of them. You have to get it early. But the one that survived is just fine. I have left the salt at the same level for about 3 weeks now, and have lowered the temp to 74. im getting ready to add some new ones soon. laters.