Ok lets walk this through step by step... Where do the bacteria in the filter come from?
The water added to the tank. How much bacteria is in tap water? Not very much.
Yes, lets walk through this step by step. First of all, bacteria are not getting into the tank via the water that is added, unless you are recycling water from another established tank. Tap water (at least any tap water from a muniple water source that treats with chlorine or some variation thereof, has zero bacteria - that is after all why we add chlorine to tap water. So the correct information from your statement would be None, rather than not very much.
As the water sits in the tank we go through a natural cycle called the maturing cycle. Whats taking place is bacteria from the water added is populating. First come the amonia bact. Then the bact. That eats ammonia start pop... (Which is where he is). Finnal the bact. That eat nitrate and nitrite. Before all the magical microbs start "colonizing" they float aimlessly through the water. Which is why 50% water change or more is way too much, ideally during this cycle you dont really want to change it that often unless u start looking at levels like 3.
Not rocket science
The cycle is called the nitrogen cycle or on aquarium forums simply cycling, not the maturing cycle. I've never see it called the maturing cycle. In the aquarium, ammonia comes first, then the bacteria that are able to convert ammonia into nitrite, then bacteria that convert nitrite into nitrate, then in some rare cases, under anaerobic conditions, bacteria that convert nitrate back into atmospheric nitrogen. The ammonia is either added by us to cycle the tank, or it is produced in the waste of the inhabitants of the aquarium. Bacteria do not "eat", nor are they magical. Once those bacteria start to occur in the water (either through direct introduction via filter materials or substrate from a mature tank) they immediately begin to colonize surfaces within the aquarium. The percentage found within the water column is small enough to be negligable in size, doing large scale water changes will not significantly impact the bacteria population, what it does do is keep the toxic levels of chemicals which are accumulating in the water at nontoxic levels.
http://www.aquariumadvice.com/forum...d-the-cycling-process-227745.html#post2144540
The filter media is only a place for bacteria to colonize... They dont come with it hence why its so clean when u pull it out of the box and gets so dirty when u change it. Lol the black stuff in it is called carbonized charcoal, all it does is add carbo to the water and attract the bact. To the ploy fiber bag. Looks like you have some research to do.
Again, this is incorrect. The black stuff is called activated carbon and what is does is remove organic wastes and some chemical substances from the water. It does not add carbon to the water, unless you fail to rinse it as directed.