If you have added seeded material to your filter it should go pretty quick. I did a 120 gallon tank back in March. I had taken the ceramic rings from two AC 110 and put them in a 75 gallon tank I had running and left them there for about a month. Once I started the 120 gallon I started adding the ammonia and it cycled in about a week. The first two days the ammonia did not drop. Then on the third and 4th day my nitrites when sky high (off the charts of my API kit). I was advised by someone to do a water change to help get out of the nitrite phase and it worked. About two days later ammonia and nitrites were at 0. I could dose it with ammonia to 2 ppm and it would be zero in 12 hours.