I was doing a fishless cycle and after 2 weeks or so I got impatient. I dropped my ammonia from 4ppm to 2ppm with a water change then I added Tetra Safestart and within 2 days my ammonia was .5ppm, nitrites 0ppm and nitrates 5ppm.
I ran to my LFS and picked up a few Danios to finish the cycle. Within the next few days the ammonia was at 0-.25ppm, nitrites 0ppm and nitrates 10ppm.
I returned the danios and stocked my 29g tank to full capacity over 2 1/2 weeks. My tank went through a mini 24 hour cycle after I put in the last 2 fish. Nitrites jumped to .5ppm and nitrates jumped to between 40-80ppm.
I did 2 pwc's 12 hours apart and added a second filter(Fluval c3). Since then my readings have been 0-0-10 to 20
This was over a period of two months.