How did this turn out? I'm in the same boat. Just did a 50% water change, super high nitrites. Ammonia is processed within 24 hours.Having the same problem. In my case ammonia is being consumed in <24h, which is a good sign. But my Nitrites have been high for 7-10 days now at least (off the Red Sea scale). I also did 2x 50% water changes and still have high Nitrites (and Nitrates). Frustrating though it can be it's really always just a waiting game in my experience