Hi Alex,
A couple of thoughts.
Do you think that the pond is getting runoff from the lawn when it rains so
hard? And is there fertilizer or herbicide on the lawn?

Do you have a mech/bio filter running on the pond?

You can read the algae primer for tips on your murky green water in the link in
my sig below.
I'll let others answer questions about salt.

Hope we can track down your problem!


kathy :-)
algae primer
http://hometown.aol.com/ka30p/myhomepage/garden.html