Hello Terry,

I also received the following answer from Richard Ott, Managing Supervisor for Inland Fisheries District 3C of the Texas Parks and Wildlife: 

The most likely cause of the murky water is the catfish themselves.  As part of their feeding behavior they stir up the bottom mud’s and contribute to the turbidity that is being described.  Fortunately, catfish do fine in the murky water because they use taste rather than sight to find their food.

Fertilizer will not clear the water and would likely contribute to additional turbidity.  What the pond owner is probably thinking about is using alum (aluminum sulfate) to flocculate the clay particles and clear the water.  Although an alum treatment might temporarily clear the water the action of the catfish would just cause it to get cloudy again.  Furthermore, repeated alum treatments can significantly decrease the pH and is not good for aquatic life. 

As catfish are removed by angling the water will probably clear on its own.

Richard  A. Ott, Jr.

Management Supervisor

Inland Fisheries District 3C

Office 903-566-2161

Cell 903-570-1871