Tom Barr advocates either soaking soil for two weeks or boiling it for two hours to mineralize the nitrogen in it - get rid of ammonia and ammonium. When I set up my tank using river silt and SM I knew I would lose my marriage if I tried to boil the silt in the kitchen, so I just poured boiling water, about a gallon at a time on the silt, stirred it, and let it sit to cool down. I did that three times, a day apart. So far I have had no problems that might indicate ammonia. So, you might want to try one of those methods.