Re: Terrestrial pathos in tank.

I have a 5 gallon glass aquarium here at work.  I don't know
how it happened, but I accidentally snipped off (stole) a 
branch of someone's terrestrial pathos plant and stuck it in 
there.  :^>  (I expected it to root).  The next day, I 
accidentally stuck another, then another.

I now have four branches in there.  After a day, the nodules
looked slightly swollen, and after 2 days I could tell they
were beginning development.  At 3 days the root nodules were
about 2mm long (no root hairs), and now we are on four
days and the nodules towards the young (terminal) end of the
branch are 5-6mm long (no root hairs yet).

Here's the curious thing.  Some of these branches have been
completely submerged the whole time.  I have a single female
betta splendens in there, and a small air stone.  I have no
UGF, but only 1-2" of gravel substrate (2-6mm).

I know that pathos is about as close to a weed as you can get,
and it grows pretty well anywhere.  Can it grow fully submerged?
I'm making the assumption that stomata is still used for
environmental exchange, and that the water is well oxygenated
so I guess the plant should have roughly the same opportunity
for collectin O2 for respiration and CO2 for photosynthesis.

In the beginning, I envisioned the roots of a terrestrial plant
simply extracting ammonia, nitrite, and nitrate from the water
(I don't have any real filtration system for nitrosommonas and
nitrobacter).  However, the plants keep sliding in there and
float just under the water surface, so they stay submerged.
They seem to be quite healthy, though, despite the high
turgidity of the leaves and stem.

I'm thinking about adding 1-2 tsp. non-iodized salt to the
tank (for the fish's benefit).  Do you think this would be a
problem for the pathos?

Anybody know about other issues to watch out for when we try
to hydroponically grow terrestrial plants?  The big one I am
aware of is root die-off under anaerobic conditions, but I don't
expect to have that problem...