On the subject of PPM, I have a question for my fellow stoners..
I have read on many many places that the ideal situation is to have a PPM level that stays pretty much the same as the plant takes up water. This "indicating that it is taking up water and nutrients at the same pace" as a way to determine that you have found the ideal nutrient mix for that stage in your plant's growth.
This doesn't really seem to make sense. Water uptake and nutrient uptake occur through two separate mechanisms. They are not joined at the hip. Maybe I am wrong, but the only way you are going to know if the mixture is right is to listen to the lady you are feeding. She won't hesitate to tell you when you fuck up. And she'll usually tell you exactly what's wrong, too.
Is there any real truth to that "steady PPM" stuff? Mine declines at a predictable, brisk, pace. Yet my plants look rather healthy to me. In fact, some of the lower leaves have nute burn! I can't imagine what they would look like if I tried to force the PPM to level off.