Herbivore Fish Foods
If your aquarium community is herbivorous (and you aren't growing live plants for them to eat) use a staple herbivore blend or supplement your fishes' diet with herbivore fish food. Spirulina is a type of blue-green algae that contains many amino and fatty acids and usually is vitamin enriched. Fish like Plecos, Silver Dollars and Mollies benefit from a diet supplemented with spirulina fish food. Also supplement with dried seaweed or algae (you may be able to feed some grazers only dried seaweed or algae, but check first).