"bo0ger1" .@. wrote in message m...
You're correct, that's where the bacteria live.

So if I culture a swab of my aquarium water
I won't find any bacteria growth?

Nobody is saying there is no bacteria in water.
She just said "that most of the bacteria that is needed
is in the rock/sand/other filtration, very little of it
in the water" - and this is true: most of the bacteria
stick to the surfaces and only small number floats in water.

Why do you think biological filters are designed to maximize
the active SURFACE if you would do equally good with just water ?