So I want to know if bacteria supplement and live bacteria actually work to speed up the nitrate cycle. My tank is about 3 weeks old. I have added both bacteria supplement and dr.tims nitrifying bacteria and my ammonia has been at a constant .5ppm the past 2 weeks. The live nitrifying bacteria has only been in for about a week, but the bacteria supplement has been in since the beginning. My nitrate readings are coming up as zero, so I'm not sure exactly what is going on. Does anyone have any suggestions? Do these products actually work? And what is a tolerable ammonia level?