It IS possible to add too much ammonia to the tank (generally several times the amounts suggested in either recipe), as some individuals discovered by mistake (thanks Boozap). What happens in this case is that the ammonia will spike very far off the chart then the nitrite will spike as well (also way off the chart), and it will continue to spike for a very long time. Why? There are a couple of possibilities... the first is that the filter media and surfaces in the tank or oxygen levels are simply insufficient to grow and maintain a bacterial colony massive enough to convert all of the ammonia and all of the nitrite to nitrates. Another likely possibility is that the ammonia levels are high enough to inhibit growth (through a biofeedback mechanism) of the bacteria rather than promoting it. The solution is quite simple, however. If you realize that you've added way too much ammonia simply do a water change, or if necessary a series of water changes to bring the ammonia and/or nitrite levels back into the readable range on your test kit. Then proceed as normal with daily additions of ammonia until the tank is cycled.
