The above information is exaggerated… There is a general concept of life “better safe than sorry” and the above suggestions are based on this as opposed to literally accurate information… I advocate the “better safe than sorry” approach, but I also advocate sharing accurate information…
　
The same species of bacteria that are common in aquarium filters thrives in dirt and even on the sides of buildings and monuments. They will die, or go dormant (depending on the species) if they are 100% dried out, but most species that likely live in our filters will do fine in a damp environment.
　
Regarding size, the range of a single bacterium is between .5~5 micrometers (micrometer = 1/1,000,000th of a meter). Some species will be slightly larger or slightly smaller, but this gives you a general idea. High powered scientific microscopes can allow us to see things of this size, but a low end microscope likely will not allow any detail to a single bacterium to be seen.
　
Chlorine does kill bacteria on contact. But tap water is not chlorine. Instead tap water contains a very small amount of chlorine. So we should not mistakenly believe that tap water will cause “instant death” to bacteria. Anytime I clean out a filter or any filter media I thoroughly rinse it with warm tap water. After 20+ years of using this method I’ve found no reason to change it.
　
I’ve looked at aquarium water under a microscope a time or two. Most of what was in it was random particles (not alive) with an occasional ‘bug’ (microbe of some sort). But not being a biologist it didn’t mean much to me.
　
My girl works in a Bio Lab at a local University. She does all sorts of weird studies using both fruit flies and bacteria. I’ve sat and watched e. coli reproduce under magnification… the stuff is freaky…
　
Random rarely know fact about our bacteria… did you know it has a tail and uses this tail to swim? It’s called a Flagellum
　
If you want to give yourself a quick education on the bacteria that lives in our filters use the terms “Ammonia Oxidizing Bacteria”, “Nitrite Oxidizing Bacteria” and “Nitrogen Cycle” While Wikipedia is not a creditable source for research papers and the like, it’s a great place to get a basic understanding on things. “The basics” will be completely accurate, it’s just when you get into ‘cutting edge’ science that it’s questionable. They also pollute it with biographical and political articles that are littered with opinions that fuel the anti wiki arguments.
