[bdement]

The popular consensus is that any fertilizer used at the recommended dosage won't kill most shrimp. The two ingredients you should be most sensitive to are Copper and Nitrogen. Copper is present only in trace amounts in most fertilizers and would take a large overdose to cause a problem. Nitrogen fertilization just isn't needed in most non-CO2 tanks.

 

[bdement]

I use Seachem trace in my shrimp tank and have never had problems. You would have to overdose an absurd amount before Copper became the problem. I would guess some other imbalance would become an issue long before Copper did with the amount that's in Trace.