I know that in large amounts ammonia will stall the nitrite consuming colonies. I also know that large amounts of nitrogen in general will displace oxygen and slow down the bacteria colonies. (Though I am not as sure for this fact, can you confirm it?)
I recently tested my source water and found I have 5ppm nitrate, which I guess could have caused the original reading but I do not find it possible it could have been responsible for my 20-40ppm nitrate right now.
Oh yeah I am doing 50% water changes every week (my source water has 0 ppm nitrite) last week when I did my 50% water change I tested right after and it was still off the charts, leading me to believe the nitrite is way up their.