What practice should be implemented to limit duckweed and watermeal?

Limiting duckweed and watermeal effectively involves addressing the factors that promote their growth in aquatic environments. The correct approach is to eliminate wastewater input, which often contains excess nutrients such as nitrogen and phosphorus. These nutrients can lead to nutrient loading in bodies of water, stimulating the growth of aquatic plants, including duckweed and watermeal.

When wastewater is removed from the equation, there is a significant reduction in nutrient availability, which in turn lessens the likelihood of excessive growth of these plants. This method is sustainable and focuses on addressing the root cause of the problem rather than managing the symptoms.

The other options do not provide an effective solution to controlling duckweed and watermeal. Increasing lighting can actually promote the growth of aquatic plants by enhancing photosynthesis. Regular application of chemical herbicides may provide short-term relief but can have negative environmental impacts and might not prevent future growth if the underlying conditions are not addressed. Creating more water flow can be beneficial in certain contexts but may not directly target the nutrient problem that supports duckweed and watermeal proliferation.