saw- if no fish in the tank you can answer that question yourself. Use the ammonia calculator to add enough ammonia to the tank to produce 3 ppm (don't forget to reduce your tank volume by 10-15%). Wait 24 hours and test. Here is how I wrote it in the cycling article:
"whenever you test and ammonia is .25 ppm or lower and nitrite is clearly under 1 ppm, it is time to add a full ammonia dose again and test in 24 hours.
If ammonia and nitrite both read 0 ppm, you are cycled. Do a large water change, be sure the water is the proper temperature, and add fish. The odds are this will not be the case quite this soon.
If ammonia and nitrite do not both read zero, continue to test daily. Whenever ammonia is again at .25 ppm or less and nitrite is clearly under 1 ppm, add the full amount of ammonia and test in 24 hours. Follow this pattern of testing and adding until both tests read 0 ppm. The cycle should not take much longer to be completed."
The above assumes one is using an API or similar test kit.
When one seeds a tank from an established tank 9or with bottled bacteria) there is no way to be certain how much bacteria has been added. So the best way to find out if a tank is ready is to follow the above procedure. A cycled tank dosed with ammonia should convert it all through to nitrate. of course well planted tanks would merely make the ammonia vanish and may never show nitrate. However, one doesn't often need to bother testing for the nitrate. If the ammonia is gone and there is no nitrite, a tank is cycled and water changes and/or plants will usually handle whatever level of nitrates there might be. Nitrate testing may help in heavily stocked tanks without plants because they will build up nitrate faster and may need more frequent water changes.