Undergravel filters, sand, and my new acquisitions (was Re: Under ground filter or not?)

[crom@cris.com (Crom)]

IMHO, the UGF has another major flaw in that it limits your choice of
substrate.  As a basic substrate, sand is *much* better than gravel.
Plants don't like gravel, and any fish that has a relationship with
the substrate doesn't like it; they much prefer sand.  In my planted
tanks, I use a bi-level substrate -- sand above soil.  Try that with a
UGF!  Another poster (perhaps the originator) to this thread mentioned
using a layer of peat over sand, another thing you couldn't do with a
UGF.  Besides, there are filters out there (wet/drys, fluidized bed,
...) that are so much more efficient and easier to clean than UGFs
that I can't understand their attraction.

Someone earlier in the thread mentioned de-nitrification in dead spots
in a UGF, an assumption I would also make.  This is one of the no-nos
people tell you about when using a UGF, though, and it's also the
reason given for only using a very fine layer of sand if sand is used.
Reefkeepers use a thick layer of sand at the bottom of their tanks,
and I don't see why a similar method wouldn't work in freshwater
aquaria.  We have our sand-sifters, the legendary Malaysian Trumpet
snail, to replace their stars and what-not.  Given, the sand they buy
is live, but anaerobic de-nitrifying bacteria will establish
themselves in any suitable substrate, will they not..

What's that abbreviation for an obligatory relevant bit?  Anyway, I
was the guy who originated the "No-Luck Nannacara" thread.  I decided
to give up on them and go with something I would at least see..  I
really wanted A. cacatouides, but there's a local shortage, so I
picked up some Microgeophagus (is that right?) altispinosa.  I picked
up two, since that's all they had. (I will probably grab a few more
when they get them in.)  These are nearly impossible to sex other than
when breeding, aren't they?  I'm a little unsure about the water
conditions they prefer.  I've read things via the WWW that say they
prefer soft, slightly acidic waters, but in Linke & Staeck, it is said
they were collected in an area of pH 7.6, and they were bred in tap
water, measuring pH 7.5 and GH and kH each of about 140 ppm (or
thereabouts -- can't remember exactly).

Thanx much,
Brian T Forsythe
crom@cris.com