Did not see any slime or mucous, he was just breathing hard and no discoloration. Would a temp spike to around 82 harm him? I realized after i found him i set the temp on the heater incorrectly to 82. When i first put him in that temp was about 78. Could the medication also caused this possibly? Some people reviewing this product online reported their fish dying day after using it.
Well IME; most medications do deplete O2 and require additional gas exchange. And there is less available O2 at higher temps. And you did say he was breathing heavy. Sorry... I should have suggested pointing a powerhead towards the surface to increase gas exchange.