Or to be more precise, how much ammonia does there need to be in the tank before the beneficial bacteria can develop? When I had my goldfish Molly, I kept the ammonia at 0.25 and the tank never did cycle. Now even with the addition of the Tetra Safe Start yesterday the ammonia level is at 1.0! Yesterday after the water change it was 0.50. So it rose that quickly with the addition of TSS! :;fru I'm not sure how often I should change the water now. Maybe I'm just being impatient and I should give the TSS a chance to work. But assuming that the TSS has failed, how much ammonia do you need for the tank to cycle?