Day 21
NO2 still >2.0ppm. Didn't bother testing NO3.
This makes watching paint dry seem exciting. I know I need to be patient but the lack of a visible trend in the #'s really does concern me. Is nitrite reducing bacteria really that hard to get to colonize?
I wonder if I have bad expectations. Is it possible the sulfur won't colonize nitrite reducing bacteria? I.e., should I just increase the flowrate now? Flush out the nitrites and let the remaining bacteria (hopefully there is some by now) just reduce the incoming nitrate?
This is far too complicated.

All I end up with is questions and more questions and no real grasp of what you're supposed to be doing.