powder tang brething but not moving

I was given a powder tang for my b-day on the 17th and now he's on the floor breathing but not moving. He had been together with a powder brown tang who constantly bullied him. A few days after I had received these fish they came up with Ich. I was guessing that this could have been because of stress with each other or maybe it was something they had before (they were no in QT because they were in my aquarium when I got home). I had to give away the powder brown and started treating the powder blue with reef safe ich formula, watching various parameters to check for changes in Ph, nitrate, nitrite, and ammonia. As of right now my ph is at 8.2, ammonia at 0, nitrate 0, and nitrite 0. I have a 90 gallon and water temp is 78.I did a 20% water change just in case. The powder blue tang was already on the floor prior to this. I woke up at 9:00 am and this is how I found him. It's been 12 hours and he's still alive. Please help!

 

the best way to get rid of ich is treat him in a seperate QT with regular unreefsafe medication. if the ich isn't that bad you can probably skip that, and turn off the lights and let him rest today.

 

so there's a slight possibility he'll live. His body almost looks rigor mortis

 

don't want to give you false hope, but you would be suprised what some tangs can take, i had tangs that have come back from being so close to death i could pick them up and they wouldn't move. at my lfs theres a blue tang that looks like its be skinned from all the gashes of other foot long tangs in the tank, its been alive for a year
good luck

 

thanks I appreciate the help!