BN pleco's eat algae all their lives. The common pleco's are the most notorious for eating it when small but preferring meatier foods as they grow. Most species of pleco are more omnivorous than BN, some are actually carnivores, and the Panaques require wood in their diet. I've bred and raised hundreds of BN on a staple diet of NLS Grow pellets, NLS 1mm Cichlid pellets, spirulina flake, and veggies at least once weekly. Used to do zucchini, but switched over to canned green beans because they're easier to work with. (They sink on their own.)