Marine salt in planted freshwater tanks?

Hi folks,
I've heard/read some recomendations to add a small amount of sea salt to
freshwater aquariums to provide trace minerals and such. Has anyone tried
this?

I have a large (125G) planted tank, with fish, and keeping the trace
elements up is tough. The fact that none of the LFS carry fertilizer makes
it even more challenging (I live in rural NH, and the only options are petco
and petquarters, neither of which is particularly good. PQ at least has a
hot FishGal though...)..

Anyway, just wondering if anyone has tried this, and what kind of results
you've had. Of course, other random opinions are welcome as well....


thanks

JD