Ugly aquarium grass, and what fish to put in a small aquarium

Hi,

I've got an Eclipse System 3 that I set up in November for my betta
(which was in a very small bowl). As an aquarium newbie, I love the
Eclipse - very quiet, easy to set up, and small enough to fit on my
desk.

Anyway, after running the aquarium with plants but no fish for a couple
of weeks, I introduced the betta (slowly). He seemed to do fine for a
week, then was suddenly quite dead one morning. :-(

So right now I'm running the tank with a couple of neons, which seem to
be doing ok, but I'm trying to decide if I want another betta, or
something else. But first I want to get my plant situation stabilized.

Here's the setup. Everything is from the local PetsMart.

Eclipse system 3. It has a built-in filter, bio-wheel, and 6-watt
florescent bulb.
I leave the light on during working hours, and turn it off at night and
on weekends.
I don't have a heater, but the water is fairly warm during the day - a
few degrees above room temperature, anyway.

Fairly large rock-gravel (from petsmart, intended for aquariums), which
is pea-sized up to about peanut m-n-m sized. I did rinse the gravel
fairly thoroughly before putting it in.
No substrate or soil or anything, because I didn't research it at all
before doing this. :-)

A small air pump, with a bubble wall extending the length of the back
of the tank. Another product plug: I spent the extra $ for a small
'Rena Air' pump, since I'm in an office and don't want to annoy my
coworkers, and I can't hear it at all over the general office noise and
the noise of the bubble wall.

Assorted small snails, that came 'for free' with the plants. I think
they are pond snails, from pictures and descriptions I've found online.
I don't really mind them, as they are kind of fun to watch scoot
around, so long as they don't interfere with the plants and fish too
much. There are a bunch of them, but they seem to have reached a
fairly steady population, as far as I can tell in this short time.

3 neon tetras (a couple have died and been replaced)

Three (maybe) ghost shrimp that I put in just for fun. I haven't seen
more than one of these at a time since I put them in, so one or two may
have died.

Several Anacharis plants - These guys seem pretty healthy. Green
leaves from root to top, and I think they are growing a bit.

A small plant that PetSmart called pennywort, but doesn't look at all
like the pictures of it I see online. He has a few inches of 'stalk',
then a couple of little branches with long-ish, slightly curved leaves.
He seems pretty healthy (green leaves, a new little sprout coming off
one side).

A Banana plant - this guy is a monster - he's putting out little
sprouts around his 'tubers' down into the rock gravel he is planted in,
has 4 leaves on small stalks and sends up 'streamers' to the surface
with nice big pretty leaves. He seems to grow visibly from the time I
get to work to the time I leave, and definately overnight. I've got a
couple of questions about him: The big surface leaves seem to last for
a few days, then 'decay'. I've been told this is pretty normal, but
should I prune the leaf when it starts to decay, or should I just let
it go naturally? Also, if I do prune it, should I cut the streamer
down close to the 'tubers', or just cut the leaf off of the streamer?
One leaf I did let just decay, and the streamer is just sitting there -
should I prune that, or will it grow a new leaf? The streamers are
really impressive - they pretty much travel the entire width of this
small tank and up to the surface, looping as they go. The streamer
with the leaf that decayed on it's own is probably two feet long - it
goes from the banana plant in the center of the tank, to one side
before looping around to the other side of the tank by the time it
reaches the surface.

Several little 'grass' clumps. These are the ones that are bothering
me. I'm not sure what species they are, but they look pretty much like
ordinary yard grass. Little clumps of long, thin, green (well, see
below...) leaves, with no 'texture', or anything. The problem I'm
having with this stuff is that while a couple of the clumps are mostly
green, most of them are an ugly translucent gray. A few leaves of the
grass fall off from time to time and get sucked up the filter, or float
on the surface until I fish them out. I'm wondering if I should yank
the poor performers out, just let them sit, prune them, or what. I'd
like to have some grassy-like stuff on the bottom of the tank to
complement the bigger and taller plants, but I also don't want to be
fooling around with rearranging plants too much, since it uproots the
plants (most of which seem to be throwing out roots despite the lack of
real soil) and puts 'junk' in the water from the gravel which will
annoy the fishes.

I haven't had any algea problems to speak of, except for perhaps an
occasional spot of what might be algea on the tank wall, that I scrub
off with a sponge intended for this purpose.

Another question: Do I need to vacuum the gravel? As I mentioned
above, the gravel is fairly large, so most of the 'junk' seems to be
settling to the bottom. I've also got these snails and shrimp in there
which seem quite happy scooting along the bottom and I assume eating as
they go. Most of the vacuum setups I've seen require a running tap,
which means I would have to move the aquarium to do it. I'm a bit
afraid of doing that without making a mess, or at least stirring up the
tank pretty thoroughly. Also, since I've got these plants covering a
fair portion of the bottom, there aren't too many places I *could*
vacuum around and between them.

I also put in the recommended amount of 'Plant Gro' once a week - it is
a liquid with trace elements and chelated iron. I've been doing a 20
oz water change once a week, using dechorinated tap water one week, and
bottled water the next (on the theory that the bottled water might be
*too* pure, and lack random nutrients the fish might need). (Yes, 20
oz is the size of the bottled water bottles. :-))

Should I consider working out a CO2 injection system? Since I've
already sunk about as much money as I can get away with into this
thing, I'd probably have to go with the 'yeast' method I've seen
online, and a mess or smell would be a very bad thing in the office.
Thanks for reading all that, and for any advice you can give!