Coppersafe + an antibiotic?

[susanp]

I treated my 2 10-yr-old feeder goldfish for ich and fin an tail rot with Maracide and Maracyn Two about a month ago.  No surprise--The ich came back, since the treatment was too short to kill the ich in the tank. (I worried about this going into to treating with Maracide).

So now I've put Coppersafe in the tank, because it lasts a month, long enough to kill off the ich in the tank.

But I'm noticing on one fish a couple of the ich spots look just a little reddish and raw, and there is a reddish color at the end of the fish's tail. This is a white fish, so it shows up well.  I'm wondering if the fish also needs an antibiotic, but now that I'm using the coppersafe, I don't know if it's safe to start treating with an antibiotic at the same time. 

I've been treating with the Coppersafe for only a few days.  Will it do enough for the ich on the fish that I can skip an antibiotic?  Or is there an antibiotic safe to use while treating with Coppersafe?  Or what is going on here?

And why do they even sell ich treatments that last only 5-7 days or whatever?