If algae is a major problem, no fish is going to keep up with it properly. Algae normally occurs with overfeeding and too much light. Try reducing the cause of algae before trying to have something eat it up. Mystery Snails do pretty well cleaning the glass even for the wisps of algae that aren't the invasive blue green algae, so if you want squeaky clean, I'd try some of those. Still, prevention is the only way to control algae.
For a more immediate fix, do a major water change and fast the tank for a day. Good luck.