Sorry for your losses! One of my tangs is currently sick too, but I decided on a different approach, and that is to simply wait it out. I know the purists here will tell you ich cannot be defeated and comes back and must be eradicated, but most horror stories involving fish losses I read involve some kind of drastic treatment, while a lot of people who just sit and wait are reporting recovery. Just my opinion. I've been in the hobby long enough to know that overeacting to any situation never leads to anything good.