lynn, right on, but q/t should be one month minimum, with freshwater dip. as for garlic, i know lots of folks love it, but the evidence in its favor appears to be anectodal at best. and, what gets me is this: where's a fish gonna get garlic in the wild? now, saute that fat tang WITH garlic, NOW you're talkin'.

q/t with f/w dip, and yes, you can copper a tang. but really, prevention is the best bet because you will always have ich/parasites/protozoans/pathogens in your sys (just as in nature), it's the animal's own defenses that you need to keep intact through ensuring good water quality and giving them the best in nutrition.
Zebrasoma scopas is my FAY-VO-RITE tang in the world. their beauty is truly sublime, and i find them to be a highly underrated fish.
too bad we don't have any "dwarf" tangs like we do angels, eh?
nasos are a big pain in the ass, but i'm prejudiced, i've had to bag 'em for ship..LOULE! also, they are, without a doubt, sh!t machines (as i just stated on another thread). but, put 'em in a 500 and baby WATCH OUT! they're all that AND a bag o' chips.