Tangs would definately prefer that you put some nori in your tank on a clip.
For those who would like to grow their own brine (read inexepensively) here's a google...
Brine Shrimp Hatcheries
However, it is important to remember than brine is like candy. You can 'survive' on candy but that is about all brine provides on it's own. For the parents out there, do you make your kids eat proteins, carbohydrates, and fats to have a balanced diet or do you let them survive on 100% Twinkies??? A Twinkie has carbs, fat, and a little protein but it is not balanced properly at all.
Neither is Brine Shrimp. While they are NOT balanced, you can enrich them by feeding them rotifers which have been enriched with greenwater. However, these are issues beyond this topic of conversation.