Ich help

[Karsten]

Hello all,

I bought a powder brown tang on Boxing Day and put it in my frag tank. In the tank there is frags, LR, snails, damsel, convict tang and now the piwder brown. I think the PBT brought in ich. It has developed white spots ect. I added Kordon Rid-Ich plus last night and this morning lots of the sps and other hard coral frags have died.

What is the best corse of action now?
Is there a way to save the frags and the two tangs?