I have a Fluval Spec V (5.5 gal) now established for 2.8 months. So far, doing well. It’s moderately planted; pressurized CO2, 6-8 shrimp (Amano and cherry), 5 tetras. I have been told to limit my water changes to 20-25% because of the shrimp. I do these water changes every other day. Under these circumstances, how do I calculate EI dosing?