Ok, I sure don't have all the tech stuff about filtration down pat. I
have a very general understanding.

Here's my question -- Why not rinse out old filter cartridges in
running tap water & reuse them?

Here's my filtration set-ups --
SMALL TANKS I use Aqua clear filters that have a sponge in the bottom &
a net bag of ceramic stuff on top of that.
LARGE TANKS I use Penguin bio-wheel filters, that take replaceable
cartridges.

Here's my limited understanding of filtration:

1. The water has to go through something to take the chunks out.
(Sponges on the Aqua clear, cartridges on the Penguins).

2. It's nice for the filter to send the water through something well
aged in the tank w/ lots of surface area for friendly bacteria to grow
on (ceramic doo hickeys on the Aquaclear, bio wheels on the Penguin.

3. Some folks like charcoal, most seem to think it's only needed to
remove medication or some other dissolved substance from the water. I
follow this latter school of thought.

4. I've seen a number of folks suggest rinsing out filter media in a
seperate container of tank water & reusing the media (presumably tank
water to preserve the bacteria), and suggestions for reusing filter
cartridge by cutting off the old filter fabric & rubber banding on new.

5. Of course the manufacuturers seem to be strong on replacing clogged
cartridge w/ brand new cartridges.

The rinsing in tank water makes sense to me, but it's a bit of a hassle
& it seems difficult to get several cartridge clean without constantly
changing the tank water in the rinse-out container.

On the other hand, it's easy for me to rinse out the cartridges (or
sponges) in hot running tap water, and it seems to get most of the
sludge out.

My reasoning was that if it's ok to totally replace clogged cartridges
w/ new ones as the manufacturers suggest, and it's ok to reuse media as
the helpful folks online suggest, wouldn't it be ok to re-use rinsed
out media, even if most of the bacteria is killed by the rinsing
process? I'm count on the never-rinsed, never-replaced ceramic dealies
and bio wheels to maintain a resonable level of good bacteria.

I've tried all methods (replace cartridges, rinse in tank water, rinse
in tap water, make your own cartridges), and all seem to work ok.

Am I missing anything? I know the charocal in the Penguin cartridges
gets used up fast, is there any harm in leaving the old charcoal (a bit
difficult & messy to remove) in the rinsed out cartridges for reuse?

Thanks in advance -- Jim