No, they are more Omnivore. They will eat algae but if it could get bloodworm, algae wafers, sinking pellets etc. as well it will be a much better and healthier Bristlenose. Like people, we can survive on chips all the time but we would be healthier if we ate meat, veggies and fruit etc. A varied diet is always better. You should try to give him different foods say three times a week and the other four days it should munch on the algae.