No, it's just hovering between the colors of 20 and 40 on the API. I'm partially colorblind, so it makes it really hard for me to tell.
I'm still changing water, but not seeing a drop. I'm not feeding much other than mysis, so I think it's leaching from the rock (which is a good thing).
I don't have any filters to change, the poly filter is more or less just to see if there are heavy metals or something weird in the tank too. AZ-NO3 isn't like dosing carbon, it bonds the nitrates to ??? and your skimmer removes it. I'm hoping that by the time the nitrates reach zero, my sulfur reactor will be kicked in and I won't need more than 1 bottle.