Hi Sandman. Sorry to hear about your loss. What I used was New Life Spectrum Thera + A. It is a sinking pellet and it comes in 2 or 3 sizes. I got the tiny pellet, because I had small mouthed fish. Most Tangs, as their name suggests, require seaweed in their diet, at least a couple times a week if not daily for some. I would use nori from the supermarket or Asian Grocery, unroasted. I would also feed mysis shrimp, cyclopeze, and ova. At least a couple times a week, I would soak any of these with GVH (garlic, vitamins, hepa...). There are lots of products like this. The key to healthy vibrant fish is a varied diet, but beware of their needs. The diet doesn't 'cure' ich, but if fish are getting all the right vitamins and nutrition, they will fight through it.
So, on days I may give a tiny pinch of Spectrum, later some mysis. The next day ova and nori, the next cyclopeze and whatever. Mix it up!