Beware of green water. There are charts online saying the cause of certain types of algae. I would shoot to induce the one that is most tasty to the plecos/snails.
However, unless these are nerite snails, I would feed algae wafers, gel food, and veggies instead of having an algae infestation. You can even culture some algae in a jar and add it to the gel food, if you like. Scraping the jar would be hard.