treatment

So I have a porcupine puffer that I just got a couple days ago, he now has ich. I have 8 assorted damnsels, maroon clown, coral beauty, yellow wrasse, and a yellow goby in the tank with him. Could I just use hypo on the whole display tank to treat the ich? If so, should I lower it all in one...

so I'm not sure if this was just a coincidence or if it inadvertently did kill off the ich in my system. Since I started my reed tank, (roughly a 1 1/2 years ago) my tank was plagued by ich, I couldn't get a fish too survice for longer than 4 months (excluding wrasses and gobies). I would...