How do I Get Rid of Watermeal Algae in a Texas Pond?

Ponds require a certain level of maintenance, especially when it comes to controlling nutrient loads that lead to weed and algae outbreaks. Prevention is the key but never 100 percent effective. The result can be menacing. One of the more difficult floating weeds to control in Texas, or any state for that matter, is watermeal. It is actually not an algae but an extremely small--in fact the smallest--floating aquatic plant. Unfortunately, this also affords it very few treatment options.

Things You'll Need

• Dip net
• Depth sounder
• Flouridone based herbicide (Sonar)
• Backpack or tank sprayer

Instructions

1. Determine the surface acreage of your pond by measuring the length and width. If circular, measure the diameter of the pond. Multiply length by width to get surface area in feet. Divide that number by 43,560 feet--the answer is your pond's surface acreage. If circular, divide the diameter by two and square the answer. Multiply the answer by pi, or 3.14, and divide by 43,560.

2. Determine the average depth in your pond. Use a depth sounder or other measurement tool to take various depth readings. Add up all the depths and divide by the number of depths recorded.

3. Determine the amount of flouridone-based herbicide necessary based on your surface acreage and average depth. Refer to the chemical's specimen label's specific rates. Always treat watermeal at 80 parts per billion (ppb)--this concentration must be achieved and maintained in your pond for at least 90 days to get a complete elimination of watermeal.

4. Agitate the chemical vigorously and add herbicide to your tank or backpack sprayer. Spray the mixture over the entire surface of the pond, ensuring an even distribution over the layer of watermeal.

References

• NewTechBio: Watermeal Control
• Sonar A.S. Specimen Label
• Purdue University: Control of Duckweed and Watermeal