Currently have a fish in cycle since 1-20. I've been checking my levels daily and my ammonia is about. 25ppm, nitrite. 25ppm and nitrate approximately 5.0ppm. I have also been doing 45% water changes every three days to help prevent stress on my fish. Last night I tested my water and my ammonia was at 1ppm, nitrite still at.25ppm and nitrate at 5.0ppm. I did a 50% water change as my last one was the night of 2-5-13. This morning I am at 0ppm ammonia, .50 nitrite and 5.0ppm. Did I do something wrong? How did I go from having 1ppm of ammonia to zero overnight?