lots of co2 lots of ferts lots of plants proper amount of light.....never had to adjust my dosing.I'm not sure about couch but i had to personalize my EI because the dosing was too high so i had to tone it down a lot.
If things start to vary you will need to start balancing your ferts and such.
mfield, are you still very lightly planted?
Rockhoer - i know you are not on co2 yet.
i summize that those two reasons are the reasons you both had to adjust your EI.
ps...its not every day that i get referred to as a couch...lol