http://www.vub.ac.be/phd/verdediging...200711071a.pdf
Good read if you are intersted in: "The main objective of this study was to describe and understand the seasonal variations of carbon and nutrient utilization by planktonic organisms in the northern Lake Tanganyika."
really short read.....really more about the chemical make up of lake tang.
Which may or may not apply to tropheus keeping. I personally want my tank to be as close to lake conditions as possible and it really does depend on which sp./variant you have.
It's a shot and simple read.....but bad at all really. Enjoy.