What type of algae? What size tank? Other inhabitants?
I always suggest finding the source of the algae problem first. But if you are simply looking so a few good to keep fish otos, SAEs, small plecs, etc. could all work.
I totally agree. Finding the source of your algae issues would be your best course of action; adding fish to keep it in check is just a band-aid solution. Keep in mind that if your plan is to breed your apistos, plecos may not be your best options.
Nerite snails would have been the best solution but I doubt your water is hard and alkaline enough as soft acidic water will erode their shells badly. If your problem is just diatoms and soft green algae, otos are good options. They won't eat green spot algae and other hard algae though.