Yellow Tang not looking good..

[Delphinus]

Do yourself a favour -- if you haven't done this already that is -- get a piece of tubing (nylon, 1/2" PVC, whatever). Find a way to attach it to the tank (e.g., food clip if you're using the flexible nylon, or drill a hole and use fishing line if using rigid tubing like PVC). Then go to the grocery store and buy a package of sushi nori. Take a half sheet and roll it over the tube.

Keep the nori in the tank 24x7. (Honest.) If he doesn't take to the nori right away, don't give up, because he will eventually. Just replace it every day. Within a week will be my bet that he'll be finishing it for you.

It truly is amazing the difference this will make for your tang.

I know it's not a specific answer to your question but I'm on a mission to make sure every tang gets fed in this manner (ie., nori in tank 24x7). A seaweed clip by itself just doesn't cut it, you'll get bits of nori everywhere. Having it rolled over tubing is key. The only bits that will come off will be the bits that he eats (so no extra food to start fouling), it will last longer for him.

Get some garlic extract or a garlic oil and squeeze some onto the nori (yeah, it's stinky but it's a good stinky). This will help him build up a resistance.

Good luck and keep us posted.