Filter Changes?

[jdesormeaux]

Hi All:

Quick question. I have a "hang on back" filter, one of the stupid ones
with the carbon inside of the cartridge that slips into the filter, and I
was wondering how often they need to be changed. I use to do it avidly every
second week but then noticed that at this time it's been 4 weeks no blockage
no measurable ammonia, no nitrites etc and my water is crystal clear,
however there is alot of goop on the filter cartages themselves.

So what do you guys think, to change or not to change that is the
question ;).

Thanks in Advance
Joey

[0rion]

"jdesormeaux" > wrote in message
t.cable.rogers.com...
> Hi All:
>
> Quick question. I have a "hang on back" filter, one of the stupid ones
> with the carbon inside of the cartridge that slips into the filter, and I
> was wondering how often they need to be changed. I use to do it avidly
every
> second week but then noticed that at this time it's been 4 weeks no
blockage
> no measurable ammonia, no nitrites etc and my water is crystal clear,
> however there is alot of goop on the filter cartages themselves.
>
> So what do you guys think, to change or not to change that is the
> question ;).
>
> Thanks in Advance
> Joey
>
>

many times with filters like these, a given cartridge can go for weeks
without change. in fact, new cartridges are typically very inefficient at
trapping non-coagulated debris (microscopic pieces) in the water column.
subsequently after a few days they become sticky and slimy enough to trap
everything. there is a very good rule of thumb for filters that rely on
gravity to pass water through the media. since the filter becomes more and
more clogged as it ages and the amount of water that goes through the pump
is relatively constant, eventually the water level behind the filter will
rise a little bit. sometimes this is very noticeable and it will even spill
over the top of the cartridge. when the water starts getting high like that,
change the media. in my smaller eclipse 15, a pump outputs onto a long
rectangular bed-shaped filter and the water passes through, downwards, and
back into the tank after hitting a bio-wheel. sometimes the floss gets
filthier and filthier and eventually the water level starts to rise... this
is when i change my filters.


remember that changing them very often (weekly or less) might actually cause
more microscopic particles to be left in the tank due to the filters not
picking it all up after they get slimy.


another thing you might want to consider is the activated carbon that you
potentially have inside your cartridge. the lifetime of the carbon might be
completely spent up before you change the filter due to mechanical symptoms
of usage. if you really need activated carbon in your tank, consider using a
small plastic net-bag or something full of it that you can change
independently of the floss media.


usually when i find it is time to change my cartridge, i use a dosage of
mardel bright'n'clear. this conditioner is a flocculant, meaning that it
binds together small pieces of matter which thereby are caught by the
filter. it also reduces phosphates, softens the water, etc. 5 hours after i
use this stuff, the filter becomes so clogged (and my water so clear) that
hardly any water passes through the filter at all- it just goes through the
emergency canal and directly onto the bio-wheel. i figure i might get one
last good usage out of my near-dead filter before i put in a new one. :)


good luck, hth


PS - dont use that mardel stuff with a new filter unless you have serious
cloudy water problems... you'll end up changing it within a day because it
gets so clogged with stuff.

[Matthew Clark]

> Quick question. I have a "hang on back" filter, one of the stupid ones
> with the carbon inside of the cartridge that slips into the filter, and I
> was wondering how often they need to be changed.

It depends how you define "changed." If you mean replacing the
activated carbon, about every month. If you mean cleaning (i.e.,
rinsing off in tank water), also every month. If you mean replacing
the whole filter cartridge, very infrequently -- say every 6 months to
a year.


Matthew Clark