Elodea is sometimes confused with Hydrilla verticallata. The major differences in the two species are that the elodea has large showy flowers while hydrilla has only small white flowers. Other major distinguishing features are that elodea is smooth to the touch if you pull a stem through your fingers, and it has serrulate leaf margins where hydrilla is rough and has sharply toothed leaf margins.
South Carolina Law requires individuals to possess a Commercial Pesticide Applicators License in Category 5, Aquatic Pest Control, before they apply aquatic herbicides if the work is done for compensation on the property of another. A license is also required, regardless of ownership, if the application is made to an area where public access to the treated site is expected. Private swimming lakes, where the public would exposed to the treated waters, are the most obvious example of the latter requirement. On all public facilities, such as golf courses, driving ranges, subdivisions, condominium/apartment complexes and mobile home parks, applicators are required to possess a Category 5 License to apply aquatic pesticides.