Shooter welcome to the forum.

I am by no means any kind of expert but I am sure some will come along shortly. Has the pond always been muddy or is this a new problem that just started? How far down into the water can you see? Do you have exposed clay around the pond that is exposed to runoff? Have you had your water tested by a lab to see the make up of the water? (A&M does this for a small cost) As Brian said there is a lot of useful information from existing post you should read.