Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
If you have a heavily stocked tank, and are therefore adding a lot of fish food that could explain higher nitrates, especially when combined with EI dosing.
I would cut the EI dosing in half and run that for a week or two.
Are you maintaining this as a high tech set up? High light, CO2?
If not, then the lower dosing of the ferts might be just right.