Shelf life of nutrients

I have these nutes that came today I don't need use it just yet and was wondering if it would still be good if not opened and what is a standed time to keep them util there no good any more ? Because there no use by date on nutes

Ive stored nutes up to about two years. Keep them in a cool dark place with lids on tight.
If i know im not gonna be using them for a while I will go in and give all of them a good shake every other week or so.. that way salts dont build up. Ive heard some nutes can get pretty chunky after a few months. What kind of nutes are they?

It's called sho gun it's a free sample for testing

I have stored nutrients for about 4 years, still as good as day one but shake regularly.