ponds without fish will eventually clear after the nutrients in the
water are used up. adding new water will send the pond back to green.
aeration is absolutely essential to clearing ponds.

the quickest way to clear a pond is with UV, but the mangled and
clumped algae must be removed from the filter to remove the nutrients.
the long term solution is a veggie filter to clean the water with or
without fish. without fish the veggies can be in the pond, with fish
the veggies need to be somewhere the fish cannot chew on their roots.
Ingrid

On Fri, 22 Jun 2007 15:09:06 -0000, wrote:
My backyard pond is failry new (this spring) and the water is always
green. I've tried the chemicals, cleaned the filter and added lillies
and other vegetation to block out the sun. Nothing works! The water is
green as ever, any suggestions?