It took me approximately 3 months keep in mind that I did nothing to jump start the process. Just added ammonia every other day. I also put the full amount of recommended Prime to treat the whole tank. I tried another brand but it did not work as well as the prime Once I started getting 0ppm for ammonia I started testing for Nitrites. Still continued to follow the same process and the Nitrites started falling and eventually went to Zero. So I am now able to convert about 4ppm of Ammonia to Nitrites in 24hrs or less. This was my first time so it was a good learning experience. Now I am trying to figure out which fish to add. Going with Chiclids (Haps and Peacocks).