More bacterial food for thought.
One thing that has not been mentioned, or if it was, I missed it. IME, aerobic bacteria constantly need a fresh substrate to grow on. When even a colony of aerobic bacteria die on decaying matter, well oxygenated water is prevented from reaching the detritus, including most anarobic bacteria. Until a fish or wind and wave action disturb the dead colony and break the "seal" to allow fresh growth, little more bacterial digestion occurs.
In my heavily stocked aquariums, when ammonia levels rise, I merely disturb the dead bacterial film on my bio-filters and the fresh bacterial growth quickly reduces the levels (quickly = within 3-5 hours). My sand filter, where the substrate is continually disturbed has never had a slow increase in ammonia. I often add 10-15 pounds of fish at a time in this 150 gallon tank. The resulting spike in ammonia and nitrates rarely lasts more than a day before levels are brought back to zero. 18 pounds of fish and nearly a half pound of food per day is pretty much the upper limit for control in this tank as ammonia will not drop below 2ppm at this density.
