"mindmeld" wrote in message
...
so, i can ditch the carbon and replace it with a sponge?...

Yes, as stated before, *unless there is a specific need for it*, carbon is
generally a waste of time and money, and will make little or no difference.
It has its uses, though.

yet... should i perhaps mention i'm not the most compulsive filter
changer/tank maintainer?


Keeping your tank in good order is important, but changing media too often
is not needed and can have a negative affect. In both my power
(hang-on-tank) and canister filters, I only service them if the water isn't
going through fast enough to suit me. I don't use carbon, so no worries
there, and as long as the media isn't gunked up and impeding water flow,
your filter is doing it's job. Every time you remove and replace a bit of
media, you're losing some of your bio-filter bacteria colony. If you remove
too much, you may end up with an ammonia spike, and a mini-cycle has to
occur before the bacteria multipy, and everything evens out again.

billy