ADA Ferts - Shelf life?

[Steve Smith]

Hi folks. I have some ADA ferts (Step 1, 2 and 3) which have been in storage for some time, about 18months. I was using them before taking down the tank I was them on. I've noticed that they seem to have changed colour a little. I was wondering if they had a shelf life, and whether I could still use them?

 

[Nathaniel Whiteside]

I think darrel stated that the dry powders have a half shelf life of a 100000000000000 years, so cant be too bad