I had a similar problem with my amazon swords. Aggressively cleaning my filter, substrate, decor and glass and adding more plants solved the problem and the new leaves grew in and didn't get algae. The less plant food and the more competition, and the few reproducing algae, the better. I really don't know, but crud can never do you good. Snails can help and make very little impact on bioload, but that may be a rabbithole you don't want to go down.
EDIT: Sometimes starving fish for a few days can convince them to eat algae, even ones that aren't 'algae eaters'. It may make them nip each other, too though.