bass, you said the bacteria are everywhere, but they are aquatic. where do they come from in a brand new tank? tap water seems somewhat reasonable but why would they live among chlorine? remember theyre aquatic, so it would make sense if they were on surfaces of things in the tank when these surfaces had been dry. so where? -__- I have been wondering this thing as well(i am sure a little research can answer my question, but I am lazy).
It would make more sense if someone takes some wet leaves from their backyard and rinses them off in their tank lol, or takes something from a local pond or river and puts that in the tank, those might be viable sources, but say people dont do that?