George, Java Fern would grow great on a rock like that. Rooted plants like
crypts, amazon etc...wouldn't do good with only a shallow "pot" and need a
couple inches of depth for substrate. Java Fern attaches itselft to
driftwood and rocks pretty easily and it gets it's nutrients from the water
column and not the substrate. Just use an elastic band to hold the plants to
the rock till they attach roots. I have Java that grows like nuts on a huge
piece of drifwood and several rocks.

Dave.

"George Pontis" wrote in message
...
What do you think about "planting rocks" ? For example:

http://www.drsfostersmith.com/produc...&Ntt=planting%
20rocks&Ntk=All&Ntx=mode+matchallpartial&Np=1&N=20 04

Looks like an easy way to incorporate some interest and dimension into the
tank,
and also maybe a way to help contain the plant environment and soils a
bit. I
bought a few of these and found that they are cast from an acrylic or
other
plastic compound, and have a pretty realistic lava rock appearance. The
surface is
much smoother than a real lava rock though, so perhaps they would not trap
and
hold food and waste as much. Inside is one or two rounded planting areas,
with a
few holes in the bottom.

Would one use a conventional soil stackup inside one of these ? Should we
expect
the roots to grow out the bottom and into the aquarium gravel, or try to
prevent
that ?

George