I have had my tank set up for about a month now. The nitrogen cycle started well. I had ammonia for about two weeks, and then Nitrites started to form. In about another week an a half nitrates started to form and the ammonia levels went almost to zero. I did a partial water change a week and a half ago and still have no signes of ammonia, nitrites, or nitrates in my tank. I feal like i should be seeing atleast some amounts of nitrates if nothing else. I have a 40 gallon planted tank with six tiger barbs. Thinks in advance.