Underground filters

I still have to disagree - the buildup of crud on the plates is actually the
bacteria colonies - they're a PITA to clean off the plates when a tank is
stripped down, but they don't cause any harm. While I have heard tales of
the "toxic gas buildup" caused by UGF, I've never experienced it, and
knowing the details of what it takes to cause it to happen, I find it very
unlikely (OK, practically impossible) for it to happen - even without
maintenance. No I know has experienced it either. Considering what it takes
for this scenario to occur in the natural world, it would be practically
impossible to hve it happen in a tank, even if you were trying to create it.
Also, the chemistry that is needed to cause the "toxic bubble" would kill
everything in the tank way before there was the possibility of enough toxic
gas developing to actually make a bubble....

Without maintenance, I can easily imagine an UGF getting matted an clogged
(actually, its the gravel that get clogged), but all that would really do is
make the filter inneffective - it wouldn't make the gravel any worse than it
would be without the UGF in place. Of course, as soon as the gravel was
vacuumed or stirred up, the filter would kick back in , and the bacteria
would repopulate the gravel pretty quickly.

I would also reiterate that a UGF is not meant to be the sole filter in a
tank. If that is how you were using them, I can understand why you would
have had problems with them. (even with a sponge filter, all you are really
providing is bio filtration - nothing else). Another factor that may be
causing you problems is the size of your tanks. Bigger tanks are always more
stable than small tanks, and a lot of the filter advances that have occurred
over the past decade or so relate to trying to make smaller tanks more
stable, making possible to have a larger carrying capacity (more fish per
gallon), and making it easier to keep both fish and plants in the same tank.
20 years ago, all of these were labour intesive, and prone to error - the
smaller the tank, the more likely it would be for an error to occur, and
quickly spiral out of control. The new technologies have made it much easier
to keep small tanks with lots of fish and plants, but they do not necesarily
perform better than some of the older technologies - it really depends on
what you want from your tank.

powerheads and high throughput canister filters are not very good for a pond
or lake setup - for fish that do not live in an environement with currents.
UGF and low-throughput filters are much better for these tanks, as they can
be run wothout creating alot of current. They ca move a lot of water through
the filter media (gravel) without introducing a current to the overall tank.

For a current environment (stream or river), powerheads and high throughput
filters are great - you want all of that flow to create the currents that
the fish "expect". In those environments, an UGF provides some ectra
buffering of the biological filtration (I am a proponent of the "more is
better" school of thought on biofilters).

I must admit that I have never bothered to keep small tanks (I consider a
5gal to be a fry tank). I would suspect that on the tiny 1,2,3 gallon tanks,
an UGF probably wouldn't make a huge difference - by the time you had a deep
enough gravel bed (2" min.), you would have taken up a lot of the tank
volume with gravel. In those tiny tanks, keeping the water volume as high as
possible is probably the most critical thing, so exxternal filtration would
probably be the way to go . Not only would the filtration not be taking up
tank volume, it would be adding ot hte total water volume by providing an
exterior "resevoir" in the filter itself....

"Tynk" wrote in message
ps.com...
On Oct 9, 7:20?am, "jd" wrote:
Yeah, I can relate with the cleaning of the crud off th e plates, but I
only
do that when I'm tearing atank down, which is hardly ever now. Since I'm
not
doing commercial or research work any more, my tanks are all
recreational,
and I don't have to tear them down unless there is a good reason. I have
tanks that have been going for 6 years without a teardown, and they're
rock
solid.....
-JD


- Show quoted text -

As you and RM mentioned...the crud under the plates is my biggest
*con* when it comes to using them.
(Pay no attention JD to the troll tailing me...we are simply
discussing the pros and cons of them and he has to make it into
something it's not...sorry *for* him).
It's that crud that is basically a ticking time bomb. Often an area of
it becomes a toxic cess pool that can release a toxic gas bubble into
the tank.
Yeah, I know that sounds pretty stupid, but it does happen and it can
kill fish.
Now that doesn't mean they're all like that, as proper maintenance
plays a huge part. However, in reality not too many are.
Another *con* for me is when there is a breakdown (either pump
failure, clog, or powerhead failure) and it can turn into a bigger
problem.
I wonder if it has to do with the crud under the plates in addition to
dying bacteria?
Maybe it's because the canister isn't actually inside the tank and a
malfunctioning canister is somewhat contained.
I like the canisters that also have a biowheel.
For folks who don't want a lot of added noise in the same room as a
large tank, such as a tv room or family room, etc...it's a better
choice than an UGF.
If noise and less equipment running isn't a concern, and they're
properly maintained, then sure...they have their purpose. I can't deny
them that.
I just find them to be a pain in the butt, and there to be better,
less noisy options out there.
I remember years ago taking out the UGF in my 29g (back then my tanks
were either run by an UGF or sponge filter or both), and taking that
first step away from them.
It was scary for me, as well as for many long time hobbyists.
After realizing there was no downfall, no *con* without it, only good
things...I've never used since. I actually toss out the new ones that
come with tank set ups, and replace it with a power filter.
Heck, even those have a long way too!
Now they have mini power filters for tiny 1g tanks.
Filtration has come a long way recently, and I just wish they would
have done it years ago. = )
When I had angels and betta spawns going, those mini power filters on
the juvie male betta male tanks would have been so usefull!