Whilst most Bristlenose eat algae, you can't rely on them to keep the tank free from algae. They do well on their own or male/female. Males are best not kept together as they may become aggressive.
If you are looking for algae eaters then Ottos would be your best bet. They prefer to be kept in groups but are best being introduced into a more mature tank.
For a tank that size though, cleaning algae off yourself will make more of an impact than algae eaters.