On Thu, 13 Aug 2009 08:17:55 EDT, Kurt
wrote:

In article ,
Galen Hekhuis wrote:

As requested, here is what the pond looks two days after I threw in
the aerator from the bank.
http://i181.photobucket.com/albums/x...g122009004.jpg
I know it doesn't look like much, but I really don't expect anything
in a hurry. In the time lapse photos you can see the duckweed blanket
move back and forth, east and west, or left and right as you look at
the picture, some 8-9 times a day. In the background, it seems like
cracks may be beginning to form, but maybe it's just wishful thinking.

Galen, oxygen (aeration) only promotes duckweed growth.
Was this a way to keep it under control? Forgive me if I didn't get
follow the thread.
Scoop the the stuff out of your pond and be prepared to continue
scooping it out as needed to keep the surface as clear as you want.
Aeration is good for the fish, since if you have any, they are starving
from the lack of open surface due to choking duckweed.
Once again, forgive me if i didn't understand this experiment.

I shovel out a bucket full of water lettuce every week from my miniscule
pond. It's healthy and there's a lot of nutrients in the water, but even
with my aerating waterfall, I need the open surface area for the fish
health.

I have a complete blanket of duckweed, I don't see how it could get
healthier. If the extra oxygen helps the duckweed, so be it. I'm
hoping (not certain) that the additional mechanical agitation will
discourage it. I have some reason to believe this by watching time
lapse photos of the pond, but I guess I'll find out for sure during
the coming months. Just as a worthless data point, while I have seen
some of the turtles in the pond actually eating the duckweed, they
don't seem to be effective at controlling it.