Is it common for the ammonia cycle to start, stop, and then start up again? When I started I was adding ammonia daily as the ammonia levels would decrease every 24 hours (but not to zero). But the past few days it has not been dropping. Is this normal, or is the cycle broken. I am in week 5-6 and this is the second time this happened. The first time it stopped I did a water change because nitrites were off the charts and it started again a few days after the w.c. Not sure if I should just wait it out or do a water change again?