Longevity of nutrients/supplies

[pantera1991]

How long do nutrients stay "good" for in general? I've had a technaflora starter kit for about 4 years now that's unopened. I also have a bottle of Collodial Silver that is about 4 years old as well that is also unopened.

Are these still safe/good to use at this point or are they too old?

 

[dadums]

The technaflora website says that the self life of their nutes is maybe one year but that they would be happy to check a product's batch number ...