I found bristle nose good algae eater. They don't get big, so they can get into small narrow spaces and crevices to clean out algae. They also self multiple easily, so you can get more to do the work. Unless you have super aggressive cichlids, they are not bothered by cichlids because of their nocturnal habit hiding during the day and come out at night to graze algae. They don't eat black beard algae though, only green algae and slime on rock and glass.