will used Seachems flourite still be good after a year?

[gopal87]

Hey all,
I found this person selling a 15pound bag of Seachem's flourite substrate for 5$. He had been using it in his tank for the past year or so. But it seems like a good deal. Would the flourite have lost its potential [nutrients/iron content etc]?
Can i go ahead and buy this? what are your opinions? a new 15Pound bag costs 32$ here.