Hi..

[...]
Heh. My experience was the complete and total opposite of
yours.

Well.., that's real life..! :-)

In our pond, elodea and hornwort grow just about as
quickly, but the
hornwort grows more densely than the elodea. I fertilize
the tank, but not the pond, which may explain the
relatively slower growth despite sunlight.

Hmm.., in our fish keeping tradition "eloda" includes
several elodea-like species. I'm mainly familiar with
Egeria densa, Elodea canadensis and Hydrilla verticilliata.
And the hornwort I mean is Ceratophyllum demersum. BTW: All
my tanks, barrels and (summer) ponds are low stocked and
planted.

Not that I'm complaining, but while there's always a stray
piece of duckweed here and there in my tanks, they never
seem to expand. I haven't yet ended up having to pull out
the netfulls that everyone seems to complain about, but
there's always a little bit in the tank and pond.

Are these tanks stocked with gold fish or colour carps..?

--
cu
Marco