I've been cycling a 8 gallon tank for almost a month and a half. I thought it might finally be ready, the ammonia was hitting zero well within 24 hours and the Nirite was almost there too. However, I dosed it the same amount I usually do on Wednesday (around 3ppm) and I've been testing it since and it's staying at 4ppm! What could have happened to my cycle?? Nothing major happened with the tank as far as heating, filtering, and lighting go.