Seaweed expiration date?

[moo0o]

I bought seaweed about 2-3 years ago for my fish tank but the tangs never eat it. I recently started up my fish tank again and have a yellow tang that hasn't been really eating the past 3-4 days. I found the same package of seaweed i bought 2-3 years ago and fed it to my fish. Will they be ok or should i buy a new pack of seaweed.

 

[Grebex11]

I recently gave a friend some that was a few years old. It was already dried, I cant imagine dried seaweed going bad... It was already dried out. Just my opinion but I think it would be fine.