On Mon, 23 Feb 2004 21:18:21 -0600, "Jessica"
wrote:

It's green water. Like Pea Soup. The pond is 15'x15'x2.5' (about 4000
gallons). We have a homemade bio filter, using lava rocks and mechanical
filters. There are a lot of pecan trees around the pond, but it still gets
lots of sun. No lilies or plant cover because I've used chemicals to treat
the algae in the past and it will kill most aqueous plants.

I think a uv filter is worth it, since this happens rapidly and about twice
a year we have to drain the pond and vacuum the algae from the bottom. This
in the Alabama and the pecan blooms and leaves are difficult to keep out of
the water.

Don't know what chemical you might have used for algae, but here is a
note I kept from the year I fought string algae:
Aluminum Sulfate 2.66 ounces per 1000 gal. (4 oz per 1500 gal.) It's
20 ppm, which is the dose recommended by the USDA. Reduces KH
removes, phosphates causes particles to coagulate.
This is only a temporary treatment for algae. It clumps the algae, so
they die, release their nutrients back into the water, to feed a
renewed algae bloom. A permanent solution is to remove the excess
nutrients, either by growing lots of plants, or by having a large
biofilter, or both. So it's somewhat futile to use alum, unless you
have the plants and biofiltration in place.

I found a UV light helps and so does Pond-Zyme, or a comparable
product to help decay the stuff that drops to the bottom.

Regards,

Hal