If treatment is finished, add fresh carbon and remove the copper. Its a poisonous metal (is why it works so well to kill ich) and you don't want to expose the fish to it any longer then you have to. Basically 3 days after the last sign of ich is an ok time to stop treating. If you haven't read this article yet, I do suggest it *grin* http://www.aquariumadvice.com/showqu...q=2&fldAuto=32
My planted tank is around 80f, my main tank around 83f. Your fish should be fine at those temps, but do remember higher temps means higher metabolism; they will eat more, be more active and not live as long.
And a suggestion if I may: look into setting up a QT. By reinfecting your fish, and treating and retreating, you are putting your fish in a bad position.
aka Cycling Guru and the Ich Slayer
*glares at Terry and QTOFFER*
Card carrying member of FTAS & GCAS.