How to Settle Clay in a Pond

Test the pH and water hardness of the pond. The pH should be above 8 and the hardness above 50 parts per million.

Pour 1 ton of crushed limestone for each acre of pond to settle the clay. Spread the rocks out with a pond rake. The limestone changes the hardness and pH of the pond water, which will help clay particles sink. Allow three or four weeks before the limestone reaches its full effect.

Plant sedges, rushes and cattails around the edges of the pond to prevent more clay from falling into the water.

Remove any rough fish from the water, such as carp, bullheads or catfish. These fish can stir up the water and prevent the clay from settling to the bottom. Prevent livestock and ducks from swimming in the pond.

Spread loose hay around the edges of the water. Use 540 pounds of hay per acre foot of the pond. If your pond is 10 feet deep and an acre large, then you will need about 5,400 pounds of hay. Apply the hay in 20- to 30-foot sections around the edges every two weeks.

Add 25 lbs. aluminum sulfate per acre foot of the pond if the pH continues to be low. Pour the sulfate around the edges of the pond.

Continue to monitor the pond and make any necessary changes every six months to keep the clay settled at the bottom.