I have been cycling for some time now (at least 3-4 weeks) and I was testing twice a day. Some days I had some exceptions where I was not as diligent with my testing, but for the most part I was. About 5 days ago I started to see small amounts of nitrate around 5ppm and I continued dosing ammonia trying to follow Sylvia's book. Now I add ammonia in the morning (enough for about 2ppm) and I test around 10-12 hours later and find no reading of ammonia, nitrites or nitrates. This has been the case for several days and I was just wondering am I cycled? My thought is maybe the plants ( some of which are about ready to be harvested) are taking in all the nitrates before I test for them? Should I have seen a much higher reading of nitrates already?