Re: Green water in open pond.

It is normal for an outdoor pond to be quite green this time of year. Water
lilies will eventually eliminate the green by shading out the algae that are
causing it. So will other aquatic plants that shade the pond. This generally
cures itself in time. The green water is really fascinating stuff if you
examine a drop under a microscope. Zillions of strange algae and little
beasties. It is the "first food" for a lot of newly hatched fry. 

There are ways of chemically precipitating the green algae from the water,
but they are only temporarily effective. There are chemical ways of killing
it also. They poison things you would rather not poison. Really, patience is
the answer, along with planting water lilies and learning to love the stuff.
(one thing that eliminates it is mosquito larvae, but I suspect that is not
an attractive solution! :-D )

One more quick "cure" - inoculate the pool with duckweed. You will soon have
clear water and a thick coating of bright green duckweed over the entire pool
surface! :-) There are several species of duckweed. I have a large-leaved
variety (individual leaves as large as 3/16 inch in diameter) that has red
undersides in bright light. I would be happy to mail "starts" of this stuff
if anyone wants some. It is quite useful, as you can easily completely
eliminate it from a pool or aquarium, in constrast to the tiny leaved stuff
that is just about impossible to get rid of.