New Grower Nutrients question

[Olderfart]

+1 on Megacrop, especially if on a tight budget.

 

[BII]

Those nutes are still good.
The amount of and ratios of elements can't change, unless oxygen and water vapor are absorbed from the air.
That would only slightly affect weight and dosage.
Expiration dates are often used to scare us into buying unneeded new products...

Yes, "the amount of and ratios of elements can't change," the same atoms will still be there, But inorganic nutrients, including large chelate complexes, presumably react and degrade over time, reducing bioavailabilty to the plant, which is what really matters; and also any organic nutes, unless sterile, will ferment and degrade over time.

So I'd be very hesitant to conclude that any nutes opened (microbial contaminated) a year or more ago, or even just sitting around for over a year, would as good as new nutes. I'd take the loss and use the old stuff out in the garden, on the lawn, etc.