Params stds. are right off of BRS and they seem to accord to any livestock I have looked at., Nutrients have been in a downwards trend since March as I also noted. I also noticed as the refugium took root, and the nutrients fell, I have a suspect that the vacuum of the NO3 and NO4 to the display, was acting like a suction, so it is likely the display side was a lot different than the filter side, although I have a robust dual circulation system. But display algae should have retreated. By now, weeks have passed and growth and lighting has been routine. I do read you. but why brown algae on the stonies stalks only in the display.... unless another actor was involved. Color me not convinced.