Join Date: Jan 2006
Location: Cherry Hill, NJ
Most nutrients are shrimp safe when dosed correctly. Excel isn't a nutrient, it is actually a modified gluteraldehyde product which is used as a disinfectant in the medical world. Usually it is safe to use, but perhaps small shrimp are sensitive to it.
If it were me, I'd use K2SO4, but you can dose using liquid ferts if you want.