Actually, I have that book on order as well as a few others...(Hoorah for E-Bay and cheap used textbooks). I do realize that the question I posed has a million
variables, but my main purpose is to get a better understanding of the nutrient relationship, especially as to how a deficiency in one nutrient can be the limiting growth factor in the presence of adequate amounts of others. Although it seems self-evident, the more I learn regarding this, the more questions I have.
Although the EI method is definately an excellent way of ensuring adequate nutrient availablilty, it leaves me with too many questions. It is seemingly impossible to state a given ppm for any nutrient without considering the nutrient assimilation by species and/or plant mass in a given water volume. Yet, I'm also beginning to understand that the variables for even the most stringent laboratory conditions would be enormous...hence, the EI method is an excellent resource for anyone wishing to maintain a planted tank without a degree in biochemistry.
My quest, then, is to understand the next level of cause and effect. To say that a deficiency in one nutrient causes yellowing leaves is not enough.
I would like to know why
? Take photosynthesis for example: (6)H2O + (6)CO2 -------> C6H12O6 + (6)O2. The role of CO2 in photosynthesis is plainly evident as shown above in the equation. The steps necessary to convert water and carbon dioxide to glucose and oxygen are extremely complex. To study the anatomy and physiology of plants and the associated chemical reactions at each level would require much more than time than I can devote. To understand the general conditions at which photosynthesis takes place is not difficult to understand. I'm looking for that next level. Not just that the leaves turn yellow, but why.