[Amy9]

I've had mine in storage for nearly 3 years. They've been in sealed containers. I'd like to start a dosing regiment and it would be nice if I didn't have to order a new batch.

 

[Seattle_Aquarist]

Hi Amy9,

The fertilizers (chemicals) we use for dosing our tanks do not lose potency over time, you should be able to use them with confidence.

 

[hbosman]

I buy the dry ferts in amounts that usually last me two years, no issues that I notice.