You need to fit a biological filter, leave out the salt and over a period of
time exchange some of the water to get rid of the salt. You don't say how
old your pond is but if you've recently filled it or put a large amount of
tap water in you will have to wait for the water to age. In time your pond
will balance itself, new ponds often go through this period of developing a
"bloom" each year. I have a pond which is nine years old, fitted with a
home - made biological filter and the pump runs 24/7 ten months of the year,
the water is crystal and I never have trouble with green water. It will also
help if you put some plants in. It is possible that you have to many fish
for the amount of water in your pond, producing to much waste, try cutting
down on the feeding, little and often is the rule.

H.

"Gary Roberts" wrote in message
...
I have tried everything I can think of - have got pump running 24 hrs a
day
with a UV filter supposely killing algy - throw pond salt in every day
(should I be doing that) - we haven't got any blanket weed or snails -
about
8 very large koi and 8 small ones live in the pond - would love it to look
crystal clear.