I keep mine in the freezer, as well. So I'm sure it lasts a lot longer than food kept under the tank. Plus, I have so many different kinds that I rotate, it just makes sense to freeze it...and I just ordered a big container of freeze-dried brine shrimp to add to this collection. The Prime Reef/Formula 2 haven't been cracked open yet, as I pre-ordered them in anticipation of adding fish to my now cycling saltwater tank. 

