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The Ongoing UGF Debate...


  1. Under ground filter or not?
    by "Darren J. Hanson" <djhanson/> (Wed, 29 Oct 1997)
    by Randy or Deb Carey <carey/> (Wed, 29 Oct 1997)
  3. reactivating a UGF
    by "Nestor10" <nestor10/> (Mon, 22 Dec 1997)
  4. To Undergravel Filter or Not?
    by "Roger S. Miller" <rgrmill/> (Tue, 2 Jan 2001)

Under ground filter or not?

by "Darren J. Hanson" <djhanson/>
Date: Wed, 29 Oct 1997
To: apisto/

At 09:37 AM 10/28/97 -0330, Robert Marshall wrote:
>Should I install an under ground filter.  Lots of opinions about no but
>no reasons why. Leaning towards get one so tell me your experiences.
>yes or no.  If no what filters should I use in addition to my Fluval 4 -
>tank is a 50 gal.  Sand, which I like, or gravel.  If I don't use a UGF
>am going to insert a layer of peat moss.

To use or not to use really depends on what you want to accomplish and what
species you are planning on keeping in your tank.

Darren and I have a business breeding fish for the wholesale outlets. In our
rearing and breeding tanks we only use Hydro sponges. This way the fry can
get all the food off the bottom. we also use Ramshorn snails for the extra
cleanup. (Very easy to control.) With the breeders tanks it's the same
setup. Mainly for the corys to get the live tubifex worms we feed them.

I'm slowly switching all our community tanks from UGF's, except for Darren's
plant tank which NEVER had a UGF, over to Hydro sponges. For us it is less
upkeep since we're constantly scooping out fish for one reason or other.
Most of the community tanks house various breeding stock that I'm not
working with at the moment.

If the tank I was setting up was for display I would use the UGF. Only
because it does keep a tank quite clear but can also cause a lot of bacteria
without proper maintenance which leads to diseases of the fish. Another
problem with the UGF for us is in our 55 grow out tanks, the quantity of
fish being housed and the small size of the fry makes it difficult to
maintain the UGF due to the inability to clean the gravel when the fry are
small. Hence, a lot of losses.

In the community tanks that I have the Hydro sponges, I also use a thin
layer (1/2") of fine sand.

Out of curiosity, why would you add a layer of peat moss?


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by Randy or Deb Carey <carey/>
Date: Wed, 29 Oct 1997
To: apisto/

George Richter wrote:

> <snip> Two -  under ground/gravel filters.  My thought is that if you really
> want a
> sewer in your tank, go for it.  I have to admit I tried them but do not
> like them.  I have had baby fish trapped by them years ago.  My fish dug
> through the gravel.  Stay away from under gravel.  Use some sort of
> sponges, even in big tanks if you like.  What's the rest of us think on
> this one?

I'll be different on this one.  I used to use mostly bare tanks with box or
sponge filters.  However, I noticed healthier behavior in the tanks with
undergravel filters.  (Realize I'm talking of all kinds of fish, not just
cichlids.)   Besides, a tank with a substrate looks better.  I think the fish
feel more secure with gravel, plants, and rocks.

Since, I have shifted much more to UG.  For my 20-longs, I use one filter with
gravel on one side, and often little or none on the other side (works well for
feeding black worms and pouring water).  Since I have valves on all of my
airlines, the airflow is gentle.

Many Apisto's will spawn in the gravel-tanks.  Since I supply PVC for Apisto
spawning sites, the fry don't get sucked into the gravel.  They are led out when
they are free swimming.  I also use bare bottomed ten-gallons for breeding
(Apistos, tetras, barbs).  Apisto's are easy so they get just pvc tubes, a box or
sponge filter, and maybe some Java Fern or Java Moss.  The tetras and barbs
require a more elaborate set up (spawning screen, et. al.).

The advantage of a box filter is that I can add carbon and replace floss as
needed, but these tend to filter from the top.  So I use both without a
preference, unless I need to use carbon.


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reactivating a UGF

by "Nestor10" <nestor10/>
Date: Mon, 22 Dec 1997
Newsgroup: rec.aquaria.freshwater.cichlids

> Why Can't you turn the UGF back on?

Can you spell a-n-a-e-r-o-b-i-c? Or perhaps a-n-o-x-i-c?

Six weeks is more than sufficient time for conditions under the gravel's
surface and especially under the filter plate to become quite obnoxious to
you and deadly to your new fry.

> There is still beneficial bacteria on the gravel and it is still doing its
job in maintaining the nitrogen cycle.

With particular emphasis to the phrase "on the gravel". This will hold true
on the surface of the gravel, where normal circulation from the sponge
filter will keep an oxygenated flow over it. I don't believe that there was
a six week oxygen supply present under the gravel when the water stopped
flowing through it.

> Turning the UGF back on will only add more oxygen to the bacteria allowing
it to work more efficiently.

As well as circulating all of the possible build up of ammonia, hydrogen
sulfide, methane and other nasties.

> And just for your info, a normal sized sponge filter does the same work as
an undergravel filter plate would do for about a 25 gallon tank.

Now this *is* true and correct, so no further comment.

> The only difference really is that waste products aren't drawn down and
eventually broken down.  Water changes take care of that for you.

Partially true. The waste products aren't drawn down into the gravel to be
decomposed, since the mechanical filtration is no longer provided by the
gravel - the sponge provides mechanical filtration instead. But there is
still trapped material in the gravel and under the plate, and it is still
decomposing and producing waste products - just not the right types now.
Water changes will remove those solid waste products that you can see, and
the end results of the breakdown process (nitrates...) that you can't.


If it is not possible for you to remove the fish to another tank
temporarily, some provision must eventually be made for cleaning the UGF in
place. You won't be able to just let it sit there - at some point in the
future you still run the very real risk of the plates releasing toxic
substances. If it *really has to be* cleaned in place, a few things you
might consider:

1. Prepare yourself for a couple - three large water changes across the same
number of days.

2. With one water change, vacuum the gravel as thoroughly as possible.

3. Prior to change number two, grab a length of thick monofilament, similar
to the weed-eater type. Push the mono down the lift tube of the UGF as far
as you can. Place the end of the mono that's still outside of the lift tube
between the palms of your hands and rub your hands back and forth to cause
the mono to jump around under the plate and hopefully knock as much of the
gunk loose as possible. Then place your siphon inside the lift tube and draw
the changewater through the plate.

4.Change number three. If you have a power head, connect a drain tube to the
output. Turn it on and let the output drain *outside* of the tank until it
runs clear. Turn off the PH, remove the drain tube and replace the expended
water. If you don't have a PH, repeat step 3 above.

That's about the best I can come up with. Perhaps someone else can expound
on the possibilities?

"chkr." is for mail-bots

To Undergravel Filter or Not?

by "Roger S. Miller" <rgrmill/>
Date: Tue, 2 Jan 2001

On Tue, 2 Jan 2001, John Pflum Jr. wrote:

> Could someone please point me to information on the pros and cons of
> having an UG filter in a planted tank?  I am considering
> removing/turning mine off but want to make an informed decision before I
> go either way.  TIA.

George Booth describes his tank setup with UGF somewhere on his website.
I can't imagine that the Krib doesn't have some discussion of the pros and
cons -- possible in the FAQ.  Our own archives contain in depth discussion
of the same topic.  Happy browsing :).

In the mean time, how about I give you a quick rundown (obviously, from my
point of view) on the pros and cons of UGF.

Both UGFs and RUGFs work in planted tanks and some people report great
success with one or both types of filter.

The principle advantage to UGF are that the setup is inexpensive and
simple; you nood no additional filtration or circulation in the tank.
They're also an easy way to get circulation to the plant roots (compare,
for instance, to the current discussion on heating cables).

The principle disadvantages to UGF are that plant roots get tangled into
the grid so plants can't be removed without damage and that the
circulation around the plant roots may be too rapid to get the best growth
in some plants.  UGF also limit your choice of substrate materials and
your ability to use substrate fertilizers and amendments.

The limitations were the clincher for me.  When I decided to stop using my
UGFs I just capped off the riser tubes near the substrate and left the UGF
plate in place.  That way (I reasoned) if it didn't work out I could just
reinstall the risers and start using the UGFs again.  Things worked out
just fine.  Now when I need to rebuild a tank for whatever reason I take
that opportunity to remove the UGF plate.  I still have unused UGF plates
in four of my six planted tanks -- I guess I don't have much need to
rebuild my setups.

Roger Miller

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