It is true, I've read, that if your tank pH is more neutral, your total ammonia levels can be higher without gill damage. ie. if your tank is at 77 degrees and pH is 7.0, apparently your total ammonia level can be 3.6 with little gill damage occurring. My tank pH seems to settle at 7.9, so my total ammonia must be kept .5 at most.
Aquaria FAQ This site has a lot of good information IMO. Click on "your first aquarium" then scroll down to the cycling section in the table of contents.
So Jake, what pH do you shoot for and how often are you doing water changes? It could very well be that by watching your pH and doing partial water changes, you are controlling the ammonia level and don't realize it.
Does this make sense to everyone, or am I confused about the whole thing?