I started a 55 gallon quarantine tank with a hang on back bio wheel filter, sump with filter sock and two bags of ceramic rings. I put a raw shrimp in and have also been ghost feeding. Ammonia was .25ppm the first two weeks and for the last week has been stuck at .50 ppm. I added Doctor Tims bacteria also because I haven't seen the ammonia start to go down. Is it normal for the ammonia to be stuck for three weeks? I feel like I should have seen the ammonia start to decrease and the nitrite start to increase by now. The ceramic rings were in a tank I had years ago. I just washed them in water and reused them. I hope they were ok to use and not contaminated with something although I don't know what it would be. This isn't my first tank but man I don't remember the first part of the cycle taking this long.