I have 2 neolamprologus bichardi and 2 neolamprologrus multi in a 20 gallon tank. What can I put with them to eat the brown algae off of the ship on my tank (I do clean the ship but i would rather not do it everytime) I clean my tank every other week, the tank does not get sunlight only tank light on half of the day but I still have brown algae. I would like to get a snail or algae eater or something to cut down the brown algae but I do not want my cichlids to bully them. What can I put with them that won't get bullied and/or will take up for itself??