Which factors may affect the growth of an Elodea plant?

Elodea is a water plant--the entire plant, including its leaves, grows under water. It is easy to maintain and is grown in many home aquariums. Even though it is under water, Elodea performs photosynthesis. Because it does, it has some of the same needs as other green plants--sunlight, carbon dioxide and water. Anything that affects the plant's access to these necessities will affect the growth of Elodea. This includes:
Murkiness of water, whether in a pond or an aquarium, will reduce the amount of sunlight available for photosynthesis and reduce the plant's growth.
Eutrophication--over-growth of algae and plant life such as Elodea due to excess fertilizer runoff--can cause first an increase (from increased nutrient levels), then a decrease in Elodea growth due to the competition for space and necessary chemicals.
Elodea is generally anchored to the soil under the water. The soil type is another factor that can affect the growth of Elodea; it grows best in a mix of sand and clay.
Elodea grows best at moderate temperatures, about 50 to 77 degrees Fahrenheit. Temperatures that are either too high or too low will inhibit growth.
https://aquaplant.tamu.edu/plant-identification/alphabetical-index/elodea/