what is the relationship between snails and Elodea?

My answer is that Elodea provides Oxygen for the snails. Is my answer correct? If not please help me.

3 answers

It is half correct. What does the snail produce for the plant?
while Elodea provide oxygen gas AND carbon dioxide, the snail only provides carbon dioxide (co2)
Elodea and Snails Overview
Elodea is a common plant used in aquariums because of the underwater beauty and its hardiness. Snails are often used in aquariums both to view and to help clean the tank of algae.

Symbiosis
The relationship between snails and elodea is symbiotic in that the snail eats algae and produces carbon dioxide. The elodea takes in the carbon dioxide and, through photosynthesis, creates oxygen, which the snail and every living thing in the tank uses to breathe.