[sirreal63]

Good job on data gathering, one thing sticks out in my mind though, how was the po4 and no3 tested? If everyone used the exact same tester then results would be more consistent, however if one person used API, another Salifert, another Red Sea or any of the numerous tests available, then the actual readings would be significantly different from one tank to another. Saying it is zero or any number lacks accuracy when a myriad of testing methods are used.

Your experience with nutrient levels mirrors my own over the years. I get better color when nutrients are higher but also an increase in algae on the glass and cyano pops up. I am dealing with it, because I want, and the corals need, the nutrients after a bleaching from an increase in light levels. I think most people rely too much on trying to replicate the nutrient levels of the reef in their tanks, our tanks do not function the way a reef does, a reef has massive amounts of food available and very low nutrients in the water. If we strip the nutrients and do not have a corresponding plethora of available food, then the corals suffer.

All of this coincides with Big E's findings as well. Sometimes we get too fixated on a number and ignore what is happening in the tank. The corals are the best indicator of proper nutrient levels for a tank, his levels may be a different number than mine, but each of our tanks has different nutrient processing abilities. There is no general correct number for any tank, but rather a number that is best for each tank, and they will not all be the same.