"Nicola B" wrote in message
...
Hi all,

wonder if you can help solve a mystery -
My pot pond is a couple of months old, roughly. Full details of pond at
bottom of post. After I had my 'pot-pond' set up for about a month or so,
a
tiny cluster of leaves appeared floating on the surface. Three tiny green
leaves. Then they started to multiply. After a few weeks (3-4), these
little
clusters covered almost 100% of the pond's surface and I noticed the water
lily looking far less happy than it had. I scooped out almost half of the
weed but it grew back again within a week. (The goldfish seems to like
eating these small leaves however.) I did not introduce this plant! I
don't
know where it came from. What *is* this weed? It seems to have little
roots
floating under it in the water.

The water of the pond is clear now, (after the expected initial
algae-fest)
the goldfish is happy and getting fatter, the other plants seem to be
doing
well. But I am worried about the water lily. It has far fewer leaves than
before. Will this weed choke it? Hope someone can help.
snip

Sounds like duckweed... http://tinyurl.com/yqdct. It's very invasive and
will easily cover a pond. On the bright side, by mid summer (in my zone 6
pond) it usually dies back, or the fish eat it all. It's a great filter
plant. My pond was a mess the first season, until (I believe) I let it cover
over with duckweed for a couple of weeks.

--
BV.
www.iheartmypond.com