I'm not convinced that PBTs or Regals are any more ich-prone that other tangs. I just think they are sold to beginners so often and they don't realize the importance of using a QT. The sheer number of these two tangs being sold shows up on our forum as more problems for these two species than others. That out of the way: tangs do not develop ich. Ich must be in the water with them. If its there, most fish will wind up with ich. If it isn't, or if the ich is killed, then no tang can get ich. IMO, all tangs should be treated in a QT under the assumption they have ich. Tank-Transfer or copper. If this treatment is done properly, and the DT is ich-free; the tangs will be ich free. I don't think any comparison between Sohals and PBTs getting ich would mean much; because there are very few Sohals compared to PBTs and Sohals tend to be bought by more experienced hobbyists. FWIW; I have a Sohal and lost another in Katrina. Both were treated with copper (prophylacticly) and I never saw a spot on them. With all the demands of keeping a Sohal, I don't think worrying about ich would even make my top ten. But if I had ich in my system, I wouldn't even consider it. Also, I'd never consider a Sohal in anything smaller than a 240; that's what mine is in and I think its too small.