Re:mutating plants with CO2


Ghazanfar K Ghori write, March 13:
>        I tried a DIY CO2 setup about 5 months ago on my heavily
>        planted 20H tank. At the time I started it the plants were
>        doing OK...wernt dieing..but were growing slowly. When I started
>        the CO2..the plant growth exploded! The melon sword was putting
>        up a bigger leaf every 5-6 days...and the hygro needed to be trimmed
>        every week cuz it shot to the surface. I noticed one thing though...
>        all the new leaves were differnt than the old non-CO2 ones. The
>        sword plant had longer leaves on short stems and the melon
>        sword had a much rounded red spotted leaf on a comparativly short
>        stem. The inter nodal space in the hygro was longer...about 1.5 "
>        if I remember correctly. I had this going for about 2 months when
>        I removed the Co2 and shifted the tank to a site near the window.
>        The plants did a lot better (sunlight) and the leaves returned
>        to their normal shapes...and the growth rate stayes more of less the
>        same cept for the hygo..which I threw out and replqaced with
>        sunset hygo..cuz it grows slower. Though now I have to hack it
>        every 10 days or so. The Java moss didnt do as weel with the Co2..
>        I think it turned knda black...though now its fine.(without Co2)
>        Anyone else expreiance this? And what that white fluffy stuff that
>        forms on the tubing where the Co2 enters the tank water?
>        Fish are fine..never had any die when I started /stopped CO2.
>        Im thinking about starting Co2 again. Just wanted to ask this stuff
>        b4 I did. thanks.
The response to the CO2 injection sounds typical.  Many plants change their
leaf shape, internodal length, etc. when given CO2 injection plus good
conditions in other areas.  Hygrophila polysperma, especially, can change
when given CO2.  Its leaves can get up to three inches long, and the edges
can become wavy.  The regular green variety can get brownish-green when it
gets near the surface.  It can grow over an inch a day, and the leaves can
get a 'swept back' look as it races along the surface.

Now that you have some sun on your tank and no CO2 injection, you may find
that some plants are out-competing others for the limited amount of CO2.
If some plants stop growing altogether, they are probably losing in the
competition for CO2.  I have had tanks where Ceratophyllum, Najas, or
Elodea took over, and the Hygrophila stopped growing entirely.

If you start up the CO2 again while the plants are getting some sun, the
growth will be even more rapid.  Consumption of nutrients will be more
rapid, also, and deficiency of something-or-other will probably show up
unless you fertilize heavily.

That white fluffy stuff is probably a colorless cyanobacterium that is
living as a saprobe (absorbing its food).  When I looked at a similar mass
with a microscope it looked like a variety of Oscillatoria.  It may mean
that you are getting along with the CO2, some of the sugar solution from
your system.

Paul Krombholz                  Tougaloo College, Tougaloo, MS  39174