By: Chad Gulley
County Extension Agent–Ag/NR
Clearing Muddy Ponds
Muddy ponds are often a problem around East Texas, especially during periods of heavy rainfall. Depending upon the fish species in your pond, muddy water can be a problem. If you are raising catfish, muddy water is not as much of a problem as catfish primarily feed by smell. If you have bass, however, bass feed by sight and must see their prey.
With the drought of 2011, many people have been cleaning out ponds. With this new dirt work, ponds may appear muddier than normal until the particles settle out. The first step in clearing a muddy pond is to inspect the watershed and shoreline for signs of erosion. Erosion control methods in these areas can prevent soil particles from entering the water source.
After rainfall events, ponds can become temporarily muddy and clearing can occur in a few days. Over populations of catfish species can keep many ponds muddy for longer periods as the catfish continually keep the pond muddy. If rainfall and catfish are not keeping the pond muddy, then the cause may be negatively charged clay particles. Remember when you were a kid and you played with two magnets. Like charges repelled each other and opposite charges attracted each other. The same is happening in your pond. Negatively charged particles are repelling each other and will not readily settle out. There are compounds you can use to help clear a muddy pond. Compounds include agricultural limestone, alum (aluminum sulfate), hydrated limestone, and gypsum (calcium sulfate). These compounds should be utilized according to the costs, availability, and effectiveness. Limestone may correct the problem as well as help to change the pH of the water if needed. An analysis of the water sample can determine how much limestone to begin with. If you want your pond water sample analyzed, contact our office and we can assist you with this.
Simple tests can be performed to determine the amount to use of these compounds. Take several one gallon samples of the pond water in glass jars. One of the gallon samples should be used for a control for comparison purposes. A second gallon jar is needed to prepare a slurry for each compound tested. At least three other samples should be treated at various rates to determine the rate and type of compound that provides the most satisfactory results.
For gypsum, mix two level tablespoons (be sure to use standard measuring spoons) of gypsum in one gallon of clear water. Stir until the gypsum is in a slurry. For alum, mix one level tablespoon (again using standard measuring spoons) of alum in one gallon of clear water. Stir until the alum is in a slurry. The lowest concentration that will precipitate the clay particles in a 12 hour period should be used to treat the pond. When using alum, be sure to add hydrated lime as well. The information and charts for conversion of the number of tablespoons of the compounds to pounds per acre-foot of water are found in the Extension publication titled Ag-402, Clearing Muddy Ponds by Don Steinbach and Dr. Billy Higginbotham.
Another important factor to consider when clearing a muddy pond is the actual size of the pond to be treated. There are formulas that can help determine the size of your farm pond. This information is found in a 2-page Extension publication titled POND MEASUREMENT DETERMINING AREA IN ACRES, VOLUME IN ACRE-FEET AND AVERAGE DEPTH by Dr. Billy Higginbotham, Professor and Extension Wildlife & Fisheries Specialist, Texas AgriLife Extension Service.
The Annual East Texas Commercial Fruit and Vegetable Conference is Tuesday, February 28 at the Tyler Rose Garden Center. Topics include micro and drip irrigation, water quality and quantity, and food safety in the morning general session. Following lunch, three concurrent sessions will be offered covering fruits, vegetables, and grapes. A $30 registration fee will be charged at the door the day of the event. Texas Department of Agriculture pesticide license holders will also receive 3 continuing education units or CEU’s. Commercial vendors will be present for those in attendance as well.
Extension programs serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin.