Fishkeeping - Cleaning Fluval 305 type filters?

I have both a 304 and 305 - as with most questions there are several
"possibilities" that can change your cleaning times but for me it is on
average once a month. Because there are two primary sponge filters I
alternate giving one a very heavy cleaning every other month. I am pretty
careful with the primary sponges because old habits tell me the bulk of the
bacteria I want are in there. Now the meat of the matter is to the ceramic
"bacteria" collectors. Mine get some algae on them and "clumps" of "stuff"
and the MOST I ever do with them is a light dunking in the water in the
filter (I never rinse or do aggressive flushing of the ceramic media, but
bacteria we want is really pretty well secured to the media). That media is
in the last (highest) basket after all the other filtration. In the lower
baskets I put some filter floss or pads and often rinse these pretty
aggressively if they are clogged. Hope that helps.

By the way some of the "possibilities" that can change your cleaning times
are how often you water change, your fish load, size of tank etc. SO for my
90 gal with 30 neons and some cats and live plants and water changes every 3
to 4 days, I can go for 60 days and not feel uncomfortable about the filter
getting too loaded. On the 50 with Oscars, plecos and artificial plants I
can't really go beyond 30 days.

"Clown" wrote in message
...
Hi, how often do people clean out fluval 305 type filters? The reason I
ask
is that mine doesn't seem to need doing for months at a time, but when I
do
it, I find that there is a lot of dirt in the ceramic biological part of
the
filter which must have been pulled through the filter sponges and its just
sitting on the ceramic nodules.

So, could it start being blown back out of the filter as it becomes
clogged?