As tempting as it can be, using fish to manage a maintenance problem doesn't usually work out too well. Plecos eat algae but they are a very heavy bioload fish. Which can lead to more algae.
Algae is the result of imbalance in a tank. Excess nutrients in the water and/or excess light. Overfeeding fish can cause excess nutrients in the water. Also being overstocked. One solution for that are fast growing floating plants like salvinia minima, Amazon frogbit. anacharis, hornwort, among others. They suck out a lot of the nutrients that would feed algae. They're great for water quality and fish like the shade and shelter they provide.
You can also manage algae by controlling the duration and/or intensity of your lighting. If your lights don't have a built in timer, you can buy an electrical timer that sets the on and off time for your lights. That's also good for fish. They need a consistent day night cycle. They have circadian rhythms too. Scale back your lighting until the algae is under control.
Live plants will always outcompete algae for nutrients. But any excess will go to algae. It's a matter of finding the balance. Enough nutrients and light for your plants to thrive but not more than that which will feed algae.
One more thing. corys and plecos can be nocturnal. If you're concerned about them getting enough food, try feeding them at night.