I ask that you stop feeding your cories "algae wafers" they are not 'algae eaters'. Most catfish are actually carnivorous, and therefore require a high protein diet. Shrimp pellets should be the staple, with occasional supplements of bloodworms (frozen are far better than freeze-dried) and other materials, like algae wafers, flake food, veggies, etc. These should be a minor portion of their diet, while the lionshare of the diet should be high protein foods like shrimp pellets.
Cories are VERY different from plecos and need to be fed accordingly.