H. difformis and top-layer muck

Steven Pushak wrote:

>I wouldn't uproot plants in a soil tank frequently for that reason but
>you can do it if you really want the roots and all. Frequently I pinch
>off stem plants at the base rather than uprooting. Most grow back.
>H. difformis is rather like a weed and the only way to get rid of it
>seems to be to uproot. If it gets overshadowed by taller plants however,
>it looses the competitive edge. 

Based on my experiences with H. difformis, it is quite a weed (a nice looking
one, though).  It doesn't do well if not rooted though, and it doesn't do
extremely well if rooted in a sterile, unfertilized substrate.  It seems to do
just fine in a "mature" substrate.  This leads me to believe that H. difformis
is a primarily root-feeding plant.  Additional factors that would tend to
support this argument are the mass of root material that you often pull up with
H. difformis when you uproot it.

>Vermiculite doesn't create a problem
>with cloudiness. Soil from an uprooting settles after a few hours.
>A lot of soil on the surface might be a problem with Corys. The 
>substrate won't get homogenous however, without quite a lot of stirring
>IMHO. ;-)

For anyone who is considering a tank that may have this type of problem, I have
solved it in my tanks.  I've mentioned my "substrate skimmer/gravel-vac"
designs before on the list.  If you're planning on setting up a plant tank with
a multigenous substrate, it is possible to build a "floor drain" for your tank
that won't drain the tank out when the pump shuts off.  The downside to this
design is that it requires a pretty big sump if you use it with a trickle-type
setup, although I don't see any reason why a cannister filter can't be hooked
up to it as well.  I use it with a settling tank on both of my currently
running setups, and have been very pleased with the low levels of substrate
muck buildup on top of the gravel (not none, just not much).  Fish that stir
the substrate (or shrimp) are also nice, since they tend to break up
accumulations.  I have found that the substrate skimmer works best with a swirl
flow in the tank, to direct debris to the center of the tank (where the drains

Photos and captions of my setup for my 20g are forthcoming.  A break-in
photo-documentary of my 55g is also in the works (a photo every week). 

David W. Webb
Enterprise Computing Provisioning
Texas Instruments Inc. Dallas, TX USA
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