I’ve had some luck with Rubbernose/Bulldog plecos eating algae. I had what was sold as a Blonde Bulldog pleco L444, and a Spotted Rubbernose L445. Both enjoyed feasting on algae growing in the tank. Especially on the rocks. They also ate everything else I normally fed like blood worms, flakes, etc.
Also, Nerite snails could be an effective alternative to the plecos if you can’t find them in your area.