Help wrasse has ich

[windcoast reefs]

So I set my new tank up last week, and when I came back from a night out of town I noticed that my solar wrasse has ich all over his body. He is still eating, but he is not as active. I have been having trouble getting my temperature back up to 78, ( currently at 73). Do you think this may be the cause? What is my next step to fixing the fish. I haven't had any luck curing ich in the past, so any sugfestions help.